So this doesn't sound like a Paypal-specific issue. The same could have happened if you accepted credit card payments through some other entity like Square.
When you accept Paypal payments, you get no access to the customer's credit card information or identification. This is either a legal interpretation that allows Paypal to push all of its risk down to its customers and make money for nothing, or the actual law is explicitly allowing Paypal to push all of its risk down to its customers and make money for nothing, but either way it's corrupt.
I’m probably wrong, but doesn’t seller protection only protect you from PayPal disputes? i.e., not bank-initiated chargebacks and fraud reports.
It wouldn’t cover item not as described, like a buyer saying you shipped a box of rocks.