Thanks, can you try the solution described in this thread:
https://social.technet.microsoft.com/Forums/en-US/5bd0f8e9-46eb-4011-a508-fb2822a16d9f/outlook-2016-rendering-problems?forum=outlook

Which version of Outlook are you using?

In that case, I would recommend creating a common "pt3agent" or "protop" user ID, that has read access to your VSTs, for all your databases and specify it in etc/protop.pf.

Hi Rob,

Are you using the same -U & -P for all your DBs? If so, you can add these parameters in $PROTOP/etc/protop.pf.

Regards,
Nectar