Had your son brought his mail in ballot with him to the polling place on election day, he could have surrendered it and voted normally.
PA IMHO stupidly went to mail in voting in 2020.. the number of provisional ballots we have to do every election now is way more than it used to be, simply because of people like your son, who request a mail in ballot, and then show up on election day to vote in person but don’t bring their mail in ballot with them to surrender.
I think in the 4-6 years prior to 2020 our district maybe did 1 or 2 maybe provisional ballots, total through all elections. Since then, its probably been in the 10 range every election. Now my polling place is small maybe 350 total voters on the rolls. So a provisional ballot isn’t the end of the world, but a busy polling place that has thousands or tens of thousands of voters voting, 3% needing to do provisional adds up to a lot of provisional votes and time spent dealing with them over a day.
Believe me, no one at the polling place is jumping for joy at having to do a provisional ballot, we’d much rather have you vote normally.
He didn’t request a mail-in ballot, they just sent it to him because he registered this year. We had no idea that he would need to take it in.