It's not a mistake. It's a feature, as they say. Paypals goal is to keep your money as long as possible preferably forever. Even if you do eventually get the money back, it is still a win for them since they gained interest on the deposits and were able to use those figures in financial disclosures etc. This is sort of why it is so hard to close your account - they would prefer their number of active users stay artificially high.
Is buying a gun not allowed in the US all of the sudden?
According to some big corps.
It is against the PayPal terms of service to buy a gun or illegal drugs with their services.
Porn is legal, but the credit card companies kicked out PornHub anyway. Not that they have ever been warm to any businesses that involve sexuality.
They closed my account two years ago because after verifying my identity they figured I was too young when I made it. That must have been over 15 years ago. There are many reports of this happening, including people losing access to the money left in their account.