Quoting this reddit thread:
I asked the voters on either side of me if they had any problems and they reported they did not. I then called over a volunteer to have a look at it. She him hawed for a bit then calmly said “It’s nothing to worry about, everything will be OK.” and went back to what she was doing. I then recorded this video.
Nothing to worry about. Especially if you're in a hurry or have poor eyesight.....
This is another data point for the superiority of vote-by-mail.