More than 200K Miss voters were marked "inactive" and forced to show up on election day and vote with a provisional ballot. This was because Miss used Experian data to verify addresses and it turns out the data was so inaccurate lots of voters were wrongly ruled inactive.
One voter is 43 and has voted in every election since he was 18. His wife and he live in the same house but he was marked as inactive because he moved, even though he didn't move. He was sent a notice he was inactive, responded to the notice to activate his voter status, including receiving notice he was now registered, and then was STILL now allowed to vote other than provisionally. He checked twice and was told his provisional vote had been denied. It was eventually allowed but he's still not sure it was actually counted.
He was one of thousands in that situation which is why the Miss Senate race has taken so long, it's such a close race all those provisional ballots essentially decided the outcome. Now remember how everytime we got an update, the lead for the Dem candidate had grown? That's because the people who had been declared inactive voters were largely Dems, it was an attempt by Republicans who controlled the election to try and block Dems from voting.