So one time when I was playing D&D as a tank, I kept failing my rolls. I don't mean like normal fails. Like 1s. All 1s. My DM also was getting criticals against me and was like "hey, you know what? You are now an NPC, because I can't keep finding creative ways for you to not die all the time."
Don't worry, I still kept failing my rolls. So this isn't a story of "oh I magically succeeded the moment he did that". I still had to roll to see if my tales of failing to success, well, succeeded. Sometimes it did, sometimes it didn't.
We honestly just felt the character was haunted or didn't like being controlled by me or something. Funny enough, dude told me someone else took my character sheet, because I left it and had the EXACT same problem.
I really shouldn't've named that barbarian of mine Numa Uhn. I really shouldn't've.