This bug has been annoying me for months. I use a feature that prints my played tracks on Spotify in the activity description. I usually add something descriptive about my ride and add that *before* the playlist.
If I use [enter] for a line break in that text, the cursor is then magically jumping to the very end of the description, and my fingers working faster than my mind often backspaces a bit, then deleting some of the playlist entries. This is clearly an input error of some kind in that particular field, and I also have an incredibly hard time selecting text over several lines, because the text is first moving slowly, then moving super fast.
This is on a fully updated iOS, the scrolling snafu mentioned towards the end might be an iOS thing, but the [enter] issue is unequivocally only present on the Strava app.