21.09.0-rc2: More aborted transactions


I just tried last RC version, but my high concurrency tests now fail because of two many aborted transactions. In those tests I have 100 go routines doing lots of queries and mutations.
With 21.03.2 my tests passed easily.

I tried setting alpha cache as before (size-mb=1024; percentage=0,65,35;) but without any success.

Are there any new changes related to transaction concurrency I’m not aware of?
Any parameter that I can set back to a previous value?