I have the same issue too, I almost feel like autocorrect hates me as it seems determined to make everything I type sound ridiculous!
It replaces perfectly normal common words with much more unusual or sometimes even nonsensical words, so it's not just that it's being a little overzealous, it just seems to be buggy. A few examples include replacing "more" with "lore", "time" with "tike", "sexist" with "sextet", "to" with "yo", "for" with "fir", and even "teen" with "reen" (which I'm not sure is even a real word?!).
What makes it extra annoying is that there is a very slight delay before the word is replaced, by which time I've already moved on to typing the next word, meaning it's easy to miss the autocorrect error if you don't double check everything you've typed!