I don't know specifically about Mississippi, and the specific voting precincts where this happened will matter, but in general, problems voting on Election Day probably favored Democrats.

Democratic voters had a lot more willingness to vote early in this election, and so a lot voted by mail nationwide; the expectation was that in-person voting on Election Day would have Republican candidates tend to catch up on vote count.

I remember some of the election coverage was talking about it, because it rained in some places on Election Day. Rain tends to depress turnout, and that rain probably favored Democratic candidates.