Pennsylvania

The provisional ballots were issued to people who came to the polls and voted in person on Tuesday, even though they requested and received a mailed ballot. They were still allowed to vote - but it's called a provisional ballot because it won't be counted until the Board of Elections has checked to make sure the person didn't already vote (by mail or in-person.) That's why provisional ballots were created - so nobody is denied their right to vote. Even if somebody shows up at the wrong poll, or there's some other glitch.

Every county is doing the same thing, but they can't count provisional ballots until the initial run has been completed. Chump will claim "voter fraud" or something else ridiculous, of course. Fraud isn't happening anywhere. All precautions have been taken to avoid errors and to prevent double voting.