One thing to try is a clean install.
Uninstall game
Manually go to folder and delete the entire Valheim folder
reinstall game and test with new save

Another thing to try if you have already done that is to go to windows time settings and toggle on and off automatic time setting and daylight saving options. Also might be an issue if you are in one of those half hour time zones.

If all else fails submit support ticket to the main website for the game. Steam is basically users helping users.

Yeah ha ha I post the same thing in the KSP forum as they use the unity engine as well.. edited to put correct game name.