for upcoming flights i affirmatively want to unrequest C+ as I really like my exit row.

Neither on the app or the website is it "sticking". I uncheck, try to do so for all legs, and the reservation still says I'm requesting upgrades for F and C+.

Now, I did call CS and they say they don't see a request for C+, only F. I may call a second time to confirm, but irrespective of what they see or don't see, it just isn't happening via app or .com.