Yet I hear those same printers worked just fine during early voting. It was not until election day that they suddenly had problems.
Mostly in Republican districts.
Everything went fine until a county worker came in and adjusted the machines.
Now that said. I have experience with scanned ballots. I saw a case where the voter had physical disability (nerve damage, vet) his control of pin did not allow him to fill the circles properly. We allowed his wife to (not modify) completely fill in the circle of a few of the positions. It went through correctly.
Maricopa county is a snake pit.