- Autocomplete on enter: Chrome does this, if I type in https://example.com (enter), it makes the mistake of autocompleting to https://example.com/some_page_I_visited_yesterday
- Arguing: Some applications that I use have autocomplete spell checkers that continue to aggressively try to "correct" technical terms, uncommon names, or company jargon that's not known. (For example, I'll cancel an autocomplete, then go back and add some punctuation, and it'll just "fix" the word again.)
- Autocomplete when the text field looses focus is a form of arguing.
- Learning typos, or incorrect learning: Libre Office started doing this. It learned some names, then it somehow learned a missed space after a common word and started continually trying to autocomplete "Electricvehicle" every time I put a space after the word "electric."
One thing that will help, in certain contexts, is the ability to unlearn or disable suggestions that frequently are canceled.