How to reproduce:
- CTRL+Alt+L locks the screen
- The lock screen contains a "switch user" button
- Going back to session with tty change doesn't unlock the session
- Using the DM to come back into the session unlocks it.
What to expect:
For Xfce there is not a switch user button. Create an additional user account before locking the screen. The new user account should show on the lock screen as selectable account.