3rd Party Add-in Intermittently Being Disabled

I have been experiencing some users where a third party add-in utilized by all 400 of our users use and require, is being disabled intermittently when opening opening Outlook/Word on startup or when Outlook/Word is closed and re-opened, even with the add in placed in the "DoNotDisableAddIn" Registry. Load behavior is "Load at Startup". Sometimes it does show up in the Slow and Disable COM Add-ins list. I would rather have Outlook/Word take longer to load than have this add-in disabled.

All the computers are LTSC 1809. Computer are running Outlook 2016.

Please let me know if any further information is needed and any suggestions or solutions would be appreciated. Thank you.