Time resets itself

Hi Guys, last week I updated my FS2020 (Simupdate 5). Everything was fine however three or four days later suddenly I haven’t been able to change my world time. A problem which is lasting until now. Every time I change the time setting (wether live or personal time) the game switches back to UTC 18:17 after a few seconds. Multiplayer is disabled, Weather and time is set to „Preset“ and I already checked the mods. Changing the server doesn’t help too. Live Weather is not affected and is functioning. I noticed disabling „online functionality“ resolves the issue but of course is something I don’t want to miss. I tried to point out which option in the „Data“ section is causing the problem but none was, only disabling whole online functionality helps. Also I tried to change the time via the developer menu – same thing. Any advice or help is appreciated!