We should sequentialize processing of messages for a thing as soon as we

get a modifying signal

* This guarantees that the next signal can be aware of the changes of the
  previous one

Signed-off-by: Yannic Klem <yannic.klem@bosch.io>

internal/utils/persistent-actors/src/main/java/org/eclipse/ditto/internal/utils/persistentactors/AbstractPersistenceSupervisor.java

@@ -588,7 +588,8 @@ private void enforceAndForwardToTargetActor(final Object message) {
      */
     protected boolean shouldBecomeTwinSignalProcessingAwaiting(final Signal<?> signal) {
         return !Signal.isChannelLive(signal) && !Signal.isChannelSmart(signal) &&
-                signal.getDittoHeaders().isResponseRequired();
+                signal instanceof Command<?> command &&
+                Command.Category.isEntityModifyingCommand(command.getCategory());
     }
 
     private void handleSignalEnforcementResponse(@Nullable final Object response,