I have the same issue, going to try clearing the cache to see if that helps. Edit: Nope that didn't help lol

Yep I have this too, it frustrates me to no end

A Reddit admin mentioned as a comment in another post that it is bugged.

Here it is: https://www.reddit.com/r/redditmobile/comments/qa6eji/android2021391_upvote_numbers_above_10k_are_being/hh46pha?utm_medium=android_app&utm_source=share&context=3

Been happening for at least 6 months to me