Fix snake_case conversion logic in Generic_Object

Corrects the condition to convert camelCase to snake_case only for keys not prefixed with '_', ensuring proper key formatting in the Generic_Object class.

Author: pfefferle

includes/activity/class-generic-object.php

@@ -205,7 +205,7 @@ public function from_array( $data ) {
 		foreach ( $data as $key => $value ) {
 			if ( null !== $value ) {
 				// Convert camelCase to snake_case if not prefixed with '_'.
-				if ( \str_starts_with( $key, '_' ) ) {
+				if ( ! \str_starts_with( $key, '_' ) ) {
 					$key = camel_to_snake_case( $key );
 				}