I suspect the majority of these votes are fake ballots.
Are you on Twitter? There’s a guy on there who goes by the handle @DissingerToupee. He’s got some insider info. on PA. He says that several thousand Philly and surrounding area registrations were delivered to Harrisburg instead of the correct voting precincts. So, when those voters went to vote on election day, they did not have registrations on file at the correct polling place and had to fill out provisional ballots. It took this long to determine the legitimacy of those ballots in theory. If they wanted to cheat, they didn’t do a great job because they still needed 20kish more to trigger the automatic recount.