Fix #18437

Author: CubikingChill

src/context/internal/globalcontext.cpp

@@ -95,6 +95,16 @@ void GlobalContext::doSetCurrentNotation(const INotationPtr& notation)
         return;
     }
 
+    // End note input on the outgoing notation to prevent stale InputState
+    // that can cause corruption when notes are entered on the new notation
+    // and propagated back via linked clones (see #18437)
+    if (m_currentNotation) {
+        auto noteInput = m_currentNotation->interaction()->noteInput();
+        if (noteInput->isNoteInputMode()) {
+            noteInput->endNoteInput(false);
+        }
+    }
+
     m_currentNotation = notation;
 
     if (m_currentNotation) {