I did that on purpose, i. e. I wanted to confirm your thoughts about uv, drifted off into a general rant, remembered OP’s original question and later realized it would have been better framed as a top level comment. In my defense, I was in an altered state of mind at the time.
Or they have the same issue as me, their phone keyboard randomly inserting periods all the time. I manually remove them most of the time, but when I’m agitated, I sometimes can’t be bothered.
This happens with several apps, e. g. https://www.reddit.com/r/Swiftkey/comments/wylng4/random_periods/
I didn’t particularly want to link to reddit, but I wasn’t able to quickly find e. g. an issue tracker.