Let me preface this by saying there should only be one takeaway from the news and polls: you still have to vote.
I’ll also note, that I’m not familiar with Tennessee elections, nor do I have any inside knowledge, so I don’t have any information to dispute what Parton said, but depending on the machine, this could be the result of old technology. Georgia had voting machines that were old enough to vote by the time the equipment was retired, so it had technology from about 2000 (think Palm Pilot technology).
I’m not sure what the age ranges are here, but one of the big selling features for the iPhone when it debuted was that it had “multi-touch” input. That meant the device could recognize the input from two inputs simultaneously — without this you would never be able to use a “pinch and zoom” gesture on a touchscreen. Prior to multi-touch, a touchscreen could only detect one input at a time, and it didn’t have any capacitive technology to distinguish between a finger and say, a coat sleeve. So if someone’s finger touched a screen at roughly the same time (or just before) a sleeve or a bracelet slid down someone’s wrist and swung enough to touch the screen, the touchscreen would still only register one input, but it might end up registering the most recent touch. Depending on the spacing and other ballot design choices, that might mean the touchscreen might register an unintended choice.
I’m not saying this is what happened in this case, but I’ve done enough voter support that my colleagues and I were able to suss out this appeared to be what happened several times, particularly with older voters. But the takeaway of all this should be, go vote, and check your ballot before casting it.

