Why can't I sign out?

Signing out needs a connection. Without one, the app shows "Cannot sign out without a connection. Try again once online: your attendance stays on this device." and the person stays signed in.

1. Get a connection back (Wi-Fi or mobile data).
2. Open Settings > Account and tap Sign out again.
3. If unsent sessions remain, the app warns that they "will be lost": wait for them to be sent (at most 30 seconds with a connection) or choose Sign out anyway.

While sign-out is refused, nothing is erased from the device: the attendance taken stays and will be sent once the connection is back. A successful sign-out erases the data kept on the device for that account. Same rule for the owner and the instructor.