I am so sorry.
I was able to resolve the problem! Sorry for stealing your time here was my solution:
After trying to upload mongoose os (Homekit) and failing i was quite sure that this shelly wont connect to the internet correctly. It also showed a green cloud but in the app it said offline.
I was quite cueless unless i set up an apache server locally and uploaded Homekit/mongoose Os again. this time it worked, in the log i was able to see that connection to time.google.com was not possible because of an DNS issue. I recalled that 1 months ago I uninstalled my Pi Hole local DNS and never changed the DNS entry in the router (second was set to cloudflare so everything else worked perfectly)
Would there be an option in shelly os to see a log where i could have found the issue?
The funny thing was that my 2 other shelly were still displaying the time correctly but maybe they just keep on running with their last state they got from a month ago.
Once again sorry for taking your time