Issues signing in on mobile devices?

We had reports from some NE Syria GBVIMS+ colleagues who were not able to log in to their Phone A52 Samsung or Galaxy Tab A7 lite. For 1 user who can log in on a mobile device, ask them to check the settings and see if the date and time set automatically (to adjust to the time zone) or manually. Depending on the answer, update the settings on the mobile device to be either automatically or manually set and then re-try logging in.