I've seen a few posts on Twitter and my dad just told me it happened to him in 2018.
Poll workers have been known to tell suspected republican voters that the ballot machine is not working at the moment and they'll send it through for you once it's back up. If this happens, tell them you will wait until it's back up. My dad and a few other voters did this and the machine miraculously started functioning again.
These cheating commies will exploit every possible opportunity to steal the vote.
This is how it always worked for me in MA, and so far every time in SC as well. Poll worker should never touch your ballot once it's given to you.