2.1.3, 2FA admin controls in user profiles do not work correctly

[LexArma]

My test sequence, pretty much exactly:

• Install 2.1.3
• Login as admin, register a second account, do not touch admin account settings yet
• Login as second account, set up 2FA, log out
• Login as admin, try to disable 2FA for second user => Nothing happens.
• Set up 2FA for admin, then try to disable 2FA for second user => SMF tells you you are about to disable 2FA for admin.
• Click Disable anyways, you will get notification that "The profile of second user has been updated successfully". (This appears to be true, and Admin retains 2FA.)

Conclusions:

1. In order to be able to disable a users 2FA, the admin MUST have 2FA set up as well - No idea why.
2. The warning message before actually doing this, doesn't recognize the edited profile correctly.
3. The 2 above may be related? Perhaps, this is a clue to why no. 1 happens.

https://www.simplemachines.org/community/index.php?topic=584984.0