Hi Socken,
Try restarting your phone and make sure the time is correct on your phone and time zone. If you still have issues try to contact Steam Support help.steampowered.com/en/wizard/HelpWithSteamIssue/?issueid=809 about this problem and they should be able to fix it for you.

Hi Socken, Try restarting your phone and make sure the time is correct on your phone and time zone. If you still have issues try to contact Steam Support https://help.steampowered.com/en/wizard/HelpWithSteamIssue/?issueid=809 about this problem and they should be able to fix it for you.