Unresponsive after upgrade to version 16

We have been running version 15 for pretty long (2 years?) and we recently upgraded to 16. It has been running for a week or two. But it becomes unresponsive. The admin interface doesn’t load (it tries, but takes 10-20minutes to get anywhere). Calls go through, but there are various small issues. The biggest one seems to be while parking a call, the call can’t be picked up.
I don’t know much of anything about asterisk and freepbx. So any help to point me in some direction of what things to look at. Logs, etc. It is running on Hyper-V 2019. There may be correlation between this issue and Dec patch tuesday updates to hyper-v. We didn’t experience this problem before then, but it was only a week or two since the 16 upgrade, so it may or may not be related to that. It may just have been that it was rebooted. A reboot fixes the problem by the way, but it comes back soon after. A fwconsole restart has helped sometimes, but not others. A httpd restart doesn’t seem to help.
There is no excessive cpu usage. Asterisk uses the most cpu, followed by mysql, which sounds normal.
This is our company’s phone system, I need HELP, I can’t have it crashing all the time. We avg about 10-20 calls going on at any given time.