diff --git a/src/org/labkey/test/util/TestDataGenerator.java b/src/org/labkey/test/util/TestDataGenerator.java
index 6f10582645..1df4ccea2a 100644
--- a/src/org/labkey/test/util/TestDataGenerator.java
+++ b/src/org/labkey/test/util/TestDataGenerator.java
@@ -52,6 +52,7 @@
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.BitSet;
 import java.util.Calendar;
 import java.util.Collections;
 import java.util.Date;
@@ -67,6 +68,7 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import static org.labkey.test.BaseWebDriverTest.ALL_ILLEGAL_QUERY_KEY_CHARACTERS;
 import static org.labkey.test.util.data.TestDataUtils.REALISTIC_ASSAY_FIELDS;
@@ -188,7 +190,10 @@ else if (fieldDefinition.getType().equals(FieldDefinition.ColumnType.MultiValueT
                     {
                         FieldDefinition.TextChoiceValidator validator =
                                 (FieldDefinition.TextChoiceValidator) fieldDefinition.getValidators().getFirst();
-                        List<String> values = shuffleSelect(validator.getValues());
+                        // Use i + 1 as a bitmask so each row gets a deterministic, non-empty subset of choices,
+                        // consistent with how other field types (Integer, Boolean, TextChoice) use i for predictable data.
+                        // Salt with queryName hash so different entity types produce distinct MVTC values at the same row index.
+                        List<String> values = bitmaskSelect(validator.getValues(), i + 1, queryName.hashCode());
                         entityData.put(key, values);
                     }
                 }
@@ -1000,6 +1005,23 @@ public static <T> List<T> shuffleSelect(List<T> allFields, int selectCount)
         return shuffled.subList(0, selectCount);
     }
 
+    /**
+     * Selects elements by index using {@code bitmask}: bit N set → include element N. Supports up to 32 elements.
+     * XORs the bitmask with {@code salt} so that callers with the same bitmask (e.g. same row index) produce
+     * different selections.
+     */
+    public static <T> List<T> bitmaskSelect(List<T> allElements, int bitmask, int salt)
+    {
+        int n = allElements.size();
+        int validMask = n < 32 ? (1 << n) - 1 : Integer.MAX_VALUE;
+        int effective = (bitmask ^ salt) & validMask;
+        if (effective == 0)
+            effective = bitmask & validMask;
+        return BitSet.valueOf(new long[]{effective}).stream()
+                .mapToObj(allElements::get)
+                .collect(Collectors.toList());
+    }
+
     public static <T> List<T> randomSelect(List<T> allOptions, int selectCount)
     {
         List<T> selected = new ArrayList<>();