Bad interactions between TalkBack and pattern-based lockscreen can lock users out

• /e/OS version: 3.0.1
• Device model(s): Teracube emerald
• Impacted Application: ~
• Affected application/URL: /
• Browser/client and version: /

The problem

Once talkback is activated, a crash can occur when making the pattern to unlock the screen, which can prevent users from unlocking their phone, see this thread for details.

Previous instructions do not work, there is no known way to deactivate talkback, rebooting to safe mode does not deactivate it.

Steps to reproduce

1. set a size 5 pattern (preferably a complicated one with extensive use of the border, particularly in the bottom left part of the dot matrix)
2. (optional but recommended) set a 2nd login method to avoid locking yourself out
3. activate talkback (by default the volume up/down combo is not activated)
4. lock the screen and try to unlock it, notice the regular crashes of the lockscreen