I mentioned in another comment that I'm using Gboard, which is Google's POS keyboard. It's not great (and I'm looking for better replacements currently), but it does learn words if you swipe them 3 or more times in a short time.

I have a unique first and last name that never pop up in dictionary words or common name lists, and Gboard swipes them for me now, because I've used them enough times in typing and fixed their attempt at autocorrecting it. Or if it mis-reads my swiped name, it's usually one of the suggested corrections across the top of the keyboard.

I really don't like Gboard, but it's been the best I've found lately, so I always install it on new phones and tablets as soon as I get them. I'm getting suggestions in another comment thread here for viable FOSS replacements, so I'll need to test those out.

Same here, all nice and good when it's English, but then switch to Hungarian or Slovak and shit breaks fast

I've been using Gboard, Google's keyboard. I don't like it and am currently trying to de-Google my life, but I haven't found a better swipe-to-text keyboard yet.

You'd think it would be easy to replace Gboard. Ever since Google started inserting AI into everything, half my words don't swipe correctly, or they'll give corrective suggestions on the top bar that are way off the mark. It was way better about 5 years ago. But it seems most keyboards are also using AI to predict swiping, so I can't find any that work better at the moment.