Question Default World Debug Stream causing massive performance loss

I recently updated my project from 2020.3.1f1 to 2020.3.15f2 and stupidly did not create a backup before doing so. After doing this my project has lost 100fps.
The culprit seems the be Default World DebugStream in Default world Unity.Entities.FixedStepSimulationSystemGroup as it is taking up around 60% of the processing time. Before updating I dont remember ever seeing the Debug stream and I was looking at the profiler a lot so im pretty sure it was not doing whatever its doing now.

What is it doing and how can I fix it?

 

Seems like a relatively minor upgrade - it should be possible to revert it, unless you upgraded packages like HDRP (which likes to upgrade all project materials). Make a backup, delete the library folder and reopen the project using the older version.

Sadly, I don't use Unity Physics so I probably can't help you with the actual problem :<

 

Seems to have worked, downgraded back to 2020.3.1f and fps is almost back to where it was before upgrading. Default world Unity.Entities.FixedStepSimulationSystemGroup is almost never in the profiler anymore but still pops up everynow and then so i would still like to know what its doing exactly.

Thanks for the help

 

I do see the same behaviour in 2020.3.27f1

Is this a confirmed issue? Is this already fixed in later versions?