I am having a similar problem. I had a PIN set. I know my PIN number. After a recent update, it appears that the PIN is no longer what I set it to. If I enter my PIN, I get a red exclamation point. Entering 0000 does not work. I am able to get to the settings and open them without a PIN, but I can no longer set a PIN or add a phone number for recovery because it is asking for a PIN and will not accept any PIN anymore.
Also, I cannot open Anti Theft anymore because it wants a PIN and will not accept my PIN or any PIN.
In a response above, you stated that if I reinstall, it will look for my old PIN, so how do I fix this and either completely clear out the PIN or make it so I can finally enter my PIN number?
Thanks.