FOP becomes erratic and unresponsive

[rnrstar]

We are having a problem with FreePBX 13 and FOP2 in that FOP will become erratic in how it reports stats and eventually it seems to crash the server to the point where Asterisk can no longer accept calls. We have experienced this on two different platforms. We initially had a Dell PowerEdge 720R and now we are on the UC400 appliances from Sangoma. What we are seeing is that Fop will report that a user is on a call but that user is no longer on the call. It will show calls in a queue but those calls are no longer in the queue. We also see from the freepbx dashboard that active calls goes higher than the number of online users. We often see 100-200 active calls when there are only 50-80 active users.

Users will also report that they are unable to change their presence or that a user shows they are still on a call when they have long ago hung up.

We also see that a caller ends up in a queue and they only hear silence instead of the hold music. Other times the call gets rejected altogether.

When we did an inspect we are seeing a couple errors.
Failed to load resource: the server responded with a status of 500 (Internal Server Error) /fop2/admin/plugins/callhistory/callhistorybs.php:1 Failed to load resource: the server responded with a status of 500 (Internal Server Error)

jquery-1.11.3.min.js:5 [Deprecation] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.

Is there a way to run FOP on a server other than the actual asterisk server?
What should we be looking for that might be causing these issues?

We are running v2.31.19