diff --git a/muted-tests.yml b/muted-tests.yml
index 6a57d9a5c3ba6..23916ea2197f5 100644
--- a/muted-tests.yml
+++ b/muted-tests.yml
@@ -515,9 +515,6 @@ tests:
 - class: org.elasticsearch.xpack.esql.vector.VectorSimilarityFunctionsIT
   method: testDifferentDimensions {functionName=v_dot_product similarityFunction=DOT_PRODUCT}
   issue: https://github.com/elastic/elasticsearch/issues/131845
-- class: org.elasticsearch.compute.aggregation.ValuesBytesRefGroupingAggregatorFunctionTests
-  method: testSomeFiltered
-  issue: https://github.com/elastic/elasticsearch/issues/131878
 - class: org.elasticsearch.xpack.restart.FullClusterRestartIT
   method: testWatcherWithApiKey {cluster=UPGRADED}
   issue: https://github.com/elastic/elasticsearch/issues/131964
diff --git a/x-pack/plugin/esql/compute/src/main/generated-src/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregator.java b/x-pack/plugin/esql/compute/src/main/generated-src/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregator.java
index 120a77fda92c6..9b5aa1ec9ae59 100644
--- a/x-pack/plugin/esql/compute/src/main/generated-src/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregator.java
+++ b/x-pack/plugin/esql/compute/src/main/generated-src/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregator.java
@@ -366,12 +366,8 @@ Block buildOrdinalOutputBlock(BlockFactory blockFactory, IntVector selected) {
             try (var builder = blockFactory.newIntBlockBuilder(estimateSize)) {
                 int nextValuesStart = 0;
                 for (int s = 0; s < selected.getPositionCount(); s++) {
-                    int group = selected.getInt(s);
-                    if (firstValues.size() < group) {
-                        builder.appendNull();
-                        continue;
-                    }
-                    int firstValue = firstValues.get(group) - 1;
+                    final int group = selected.getInt(s);
+                    final int firstValue = group >= firstValues.size() ? -1 : firstValues.get(group) - 1;
                     if (firstValue < 0) {
                         builder.appendNull();
                         continue;
diff --git a/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregators.java b/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregators.java
index 20ec7b08f9cb7..8448d28015e1c 100644
--- a/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregators.java
+++ b/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/ValuesBytesRefAggregators.java
@@ -160,8 +160,8 @@ static void addOrdinalInputBlock(
         IntVector hashIds
     ) {
         for (int p = 0; p < groupIds.getPositionCount(); p++) {
+            final int groupId = groupIds.getInt(p);
             final int valuePosition = p + positionOffset;
-            final int groupId = groupIds.getInt(valuePosition);
             final int start = ordinalIds.getFirstValueIndex(valuePosition);
             final int end = start + ordinalIds.getValueCount(valuePosition);
             for (int i = start; i < end; i++) {
@@ -212,8 +212,8 @@ static void combineIntermediateInputValues(
         } else {
             final BytesRef scratch = new BytesRef();
             for (int p = 0; p < groupIds.getPositionCount(); p++) {
+                final int groupId = groupIds.getInt(p);
                 final int valuePosition = p + positionOffset;
-                final int groupId = groupIds.getInt(valuePosition);
                 final int start = values.getFirstValueIndex(valuePosition);
                 final int end = start + values.getValueCount(valuePosition);
                 for (int i = start; i < end; i++) {
diff --git a/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/X-ValuesAggregator.java.st b/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/X-ValuesAggregator.java.st
index 017c5540c98f0..3641a17ce6972 100644
--- a/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/X-ValuesAggregator.java.st
+++ b/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/X-ValuesAggregator.java.st
@@ -525,12 +525,8 @@ $if(BytesRef)$
             try (var builder = blockFactory.newIntBlockBuilder(estimateSize)) {
                 int nextValuesStart = 0;
                 for (int s = 0; s < selected.getPositionCount(); s++) {
-                    int group = selected.getInt(s);
-                    if (firstValues.size() < group) {
-                        builder.appendNull();
-                        continue;
-                    }
-                    int firstValue = firstValues.get(group) - 1;
+                    final int group = selected.getInt(s);
+                    final int firstValue = group >= firstValues.size() ? -1 : firstValues.get(group) - 1;
                     if (firstValue < 0) {
                         builder.appendNull();
                         continue;
diff --git a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesBytesRefGroupingAggregatorFunctionTests.java b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesBytesRefGroupingAggregatorFunctionTests.java
index a1367bee53340..fa274ef05c5fe 100644
--- a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesBytesRefGroupingAggregatorFunctionTests.java
+++ b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesBytesRefGroupingAggregatorFunctionTests.java
@@ -27,6 +27,9 @@
 import static org.hamcrest.Matchers.nullValue;
 
 public class ValuesBytesRefGroupingAggregatorFunctionTests extends GroupingAggregatorFunctionTestCase {
+    final boolean ordinals = randomBoolean();
+    final boolean withNulls = randomBoolean();
+
     @Override
     protected AggregatorFunctionSupplier aggregatorFunction() {
         return new ValuesBytesRefAggregatorFunctionSupplier();
@@ -39,10 +42,17 @@ protected String expectedDescriptionOfAggregator() {
 
     @Override
     protected SourceOperator simpleInput(BlockFactory blockFactory, int size) {
-        return new LongBytesRefTupleBlockSourceOperator(
-            blockFactory,
-            IntStream.range(0, size).mapToObj(l -> Tuple.tuple(randomLongBetween(0, 4), new BytesRef(randomAlphaOfLengthBetween(0, 100))))
-        );
+
+        return new LongBytesRefTupleBlockSourceOperator(blockFactory, IntStream.range(0, size).mapToObj(l -> {
+            long groupId = randomLongBetween(0, 100);
+            if (withNulls && randomBoolean()) {
+                return Tuple.tuple(groupId, null);
+            }
+            if (ordinals && randomBoolean()) {
+                return Tuple.tuple(groupId, new BytesRef("v" + between(1, 5)));
+            }
+            return Tuple.tuple(groupId, new BytesRef(randomAlphaOfLengthBetween(0, 100)));
+        }));
     }
 
     @Override
diff --git a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesDoubleGroupingAggregatorFunctionTests.java b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesDoubleGroupingAggregatorFunctionTests.java
index b89612a52c682..d936aa72e868a 100644
--- a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesDoubleGroupingAggregatorFunctionTests.java
+++ b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesDoubleGroupingAggregatorFunctionTests.java
@@ -26,6 +26,8 @@
 import static org.hamcrest.Matchers.nullValue;
 
 public class ValuesDoubleGroupingAggregatorFunctionTests extends GroupingAggregatorFunctionTestCase {
+    private final boolean withNulls = randomBoolean();
+
     @Override
     protected AggregatorFunctionSupplier aggregatorFunction() {
         return new ValuesDoubleAggregatorFunctionSupplier();
@@ -40,7 +42,8 @@ protected String expectedDescriptionOfAggregator() {
     protected SourceOperator simpleInput(BlockFactory blockFactory, int size) {
         return new LongDoubleTupleBlockSourceOperator(
             blockFactory,
-            LongStream.range(0, size).mapToObj(l -> Tuple.tuple(randomLongBetween(0, 4), randomDouble()))
+            LongStream.range(0, size)
+                .mapToObj(l -> Tuple.tuple(randomLongBetween(0, 100), withNulls && randomBoolean() ? null : randomDouble()))
         );
     }
 
diff --git a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesFloatGroupingAggregatorFunctionTests.java b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesFloatGroupingAggregatorFunctionTests.java
index 7dc550abd4e49..7f6f3345d7cf8 100644
--- a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesFloatGroupingAggregatorFunctionTests.java
+++ b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesFloatGroupingAggregatorFunctionTests.java
@@ -26,6 +26,8 @@
 import static org.hamcrest.Matchers.nullValue;
 
 public class ValuesFloatGroupingAggregatorFunctionTests extends GroupingAggregatorFunctionTestCase {
+    private final boolean withNulls = randomBoolean();
+
     @Override
     protected AggregatorFunctionSupplier aggregatorFunction() {
         return new ValuesFloatAggregatorFunctionSupplier();
@@ -40,7 +42,8 @@ protected String expectedDescriptionOfAggregator() {
     protected SourceOperator simpleInput(BlockFactory blockFactory, int size) {
         return new LongFloatTupleBlockSourceOperator(
             blockFactory,
-            LongStream.range(0, size).mapToObj(l -> Tuple.tuple(randomLongBetween(0, 4), randomFloat()))
+            LongStream.range(0, size)
+                .mapToObj(l -> Tuple.tuple(randomLongBetween(0, 100), withNulls && randomBoolean() ? null : randomFloat()))
         );
     }
 
diff --git a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesIntGroupingAggregatorFunctionTests.java b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesIntGroupingAggregatorFunctionTests.java
index 7368ed285ddb6..7b902ed5194c8 100644
--- a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesIntGroupingAggregatorFunctionTests.java
+++ b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/aggregation/ValuesIntGroupingAggregatorFunctionTests.java
@@ -40,7 +40,7 @@ protected String expectedDescriptionOfAggregator() {
     protected SourceOperator simpleInput(BlockFactory blockFactory, int size) {
         return new LongIntBlockSourceOperator(
             blockFactory,
-            LongStream.range(0, size).mapToObj(l -> Tuple.tuple(randomLongBetween(0, 4), randomInt()))
+            LongStream.range(0, size).mapToObj(l -> Tuple.tuple(randomLongBetween(0, 100), randomInt()))
         );
     }