Performance Issues?

Recently [Sugar Enterprise 8.3.0] my Sugar Instance has had A LOT of performance issues.

Continuous logouts, HTTP500 issues, Cross-Site Forgery issues, and problems with Token Authentication.
There is not pattern to these issues. All users are experiencing it. The tickets I'm putting in never seem to lead anywhere.

We have a Quickbooks Connector, RIVA for email logging and TenFold to integrate RingCentral.

Does anybody have similar experiences lately (the past 2 weeks).

Clearing cache and browser history doesn't seem to help anything.

Hoping to find some advice to help the end users experience.