SmorgasbordQ Thanks a lot for your report and reproducer.

This is quite embarrassing, and my only relief is that we reworked that part in Hibernate Search 6 which means this will only affect Hibernate Search 5.11 and maybe 5.10 (I didn’t check yet), but not later versions.

For the record, the problem is not that the executors don’t handle tenants, but that we have some optimization logic that picks one executor or another depending on requirements (multitenancy or not, …), and in some cases that logic picks the wrong one (which doesn’t handle tenants, even though others do).

I will work on a fix.