hi dimitris, would you be able to capture and share a performance profile while the problem is apparent?

https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Reporting_a_Performance_Problem

Hi Phillipp,

https://perfht.ml/2KgLDFD

Many thanks, Dimitris

thanks, are you able to reproduce the hangs in firefox safemode as well? it looks like it may be a graphics issue, so updating your graphics drivers might help as well...

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

It seems to be working fine in safe mode. Way speedier than normal, to be honest.

I'm on a Hyper-V VM, not possible to update video drivers I'm afraid... The issue is replicated on two different hyper-v servers (using the same OS image thought).

Since the last firefox update when the issue started occuring, there weren't any changes to the VM or the underlying hypervisors.

Thanks

in this case i'd try to keep hardware acceleration disabled in Firefox's performance settings.

Yeah, fair enough.

Disabling the acceleration seems to have helped.

Now the CPU usage goes a bit mental when rendering pages but looks like the annoying 5 sec freezing is no more.

I'll keep it disabled for the time being as it looks the workaround has helped, hoping a future release (or an MS patch) will fix it properly.

Thanks, Philipp Much appreciated.

Regards, Dimitris