One day, I've noticed that the pattern I always use to unlock my phone and the recovery PIN don't work (never gave it to anyone nor have changed it since I initially put them in). I unlocked it using my Google account, but now the lock screen is stuck to Swipe. I then went to the Screen Lock setting and changed it to PIN, but not only has it not changed from Swipe, but the setting is now protected by a PIN, of which the PIN I used doesn't work.
What do I do now to get rid of that PIN without having to fully reset my phone?