Does nobody have a idea? Dont know what to do anymore.
Ive re-installed outlook. Im about to setup the whole pc new which will be very complicated and probably dont solve this matter.

I have a small update: By unclicking the Exchange-Cache-Mode the problem got "kinda" solved. It worked for a few days but now it somehow set itself back and everything she had labeled disappeared....

It works again now but I fear that this will disappear again....