So I think the "2.7 Million Votes Changed" thing is only showing errors in IBM's election results service. The data source was an NY Times "Edison" feed that was scraped, right? Edison is the name of an IBM Election service, which probably scrapes results from State/County websites and aggregates them in a way that easily consumable, and sending them out to those willing to pay for the service in real time. Very likely that Edison's election reporting has the faults in it. You'd have to prove this back from Edison to the vote tallies, which is different question.

https://www.edisonresearch.com/election-polling/#two