I will do whatever needs to be done to get this solved for you.
We are releasing an update next week. I would suggest that the day we release it (I’ll announce it in the forum) you try a clean install, then see if the issue with the mini viewer and themes is fixed or not. If not I’ll open a ticket with our team and we’ll do some very detailed information gathering with your help to find exactly why this happens, then we’ll get it fixed.
Sound OK? I apologize for the delay but I think waiting for the next release is the best solution because it could automatically fix your problem.