Hello Nerbert Fekkes,
unfortunately i cannot give you any solution to this problem. But at least i can confirm that setting the ParallelMassQueries=1 command line parameter, does nothing in Unreal Engine 5.3.
The operations performed in the entity queries of a processor are always processed serially. No matter if they are executed in the GamThread or a WorkerThread (bRequiresGameThreadExecution = false / true). Also processors of the “Representation Group”, which will update the Actor (LowRes / HighRes Actor MassGameplay representation) will only be executed in GameThread no matter if bRequiresGameThreadExecution is set to false.
I guess currently the only solution is to spread the processing to multiple processors which should be executed in parallel on multiple worker threads? For e.g. by using some different MassTags.
With best regards, Torsten