when I select a flight and set a time of day incl. the month, my time and season jumps back to 07/30 and it is “dark” around 23:00.
My initial weather is “default” and when I change the weather and date, it always jumps back to 07/30/2021 after a few seconds…!"
Also when I set it to “live-weather” (real time) it jumps back to 07/30/2021 after a few seconds, I didn’t change anything in the settings, it was running a few days ago…!"
Does this have something to do with the live weather problem that has been known for a few days…?
No it shouldn’t.
Where are you changing the time from?
Ensure in the world map, near the top right, under “Flight Conditions”, you have “Weather and Time” set for “Custom”.