Possible bug: character was input into screensaver

I was looking at my locked screen while being away from the computer, and to my surprise it attempted to login and failed. It looked like 1 character was input, and then enter hit. It visibly failed in front of my eyes with no hands on the keyboard.

I don’t think I’ve been hacked, I think there’s a bug somewhere, especially as I was messing with lock screen settings. But I have no idea or explanation for how that could have happened. Most unsettling bug I’ve seen for sure.

could also be issue with keyboard, something to do with electricity, i also have this issue where my c key keeps getting spammed sometimes until i press on it once on a lenovo laptop