This behavior might be caused by skipping time in the game.

If you adjusted the date/time of your device, you'll have to change it back and wait for the in-game timer to catch up with the date you skipped to in order to fix the problem. Keep in mind that this does not fix the problem immediately, and it will take some time for your game to catch up.

Generally, we advise against time skipping because it often leads to unintended errors and interferes with internal game timers and spawn rates.