A Bug About Time

When I entered a newly created GAME, I discovered a very interesting bug. The time "06:12:00" displayed in the upper right corner will change to "00:00:00" within one second. When entering the game a few times ago, the time will be reset like this. I didn't find out how this problem was triggered, nor did I find out how it ended.
This problem occurs in Vanilla's planetary system, or other systems I downloaded.