The type of glitch we're talking about here is a machine set to think that the "trump" bubble is the "biden" bubble - aka, there's a position offset issue.

So either the machine didn't receive the software update required to change from whatever ballot it was previously processing, or it received a fraudulent software update.

That's not a glitch. It's either oversight or fraud, and would be easily solved by requiring two observers at every step of the election process.