Maybe that’s part of it, but I’ve also noticed autocorrect on my devices often correcting incorrectly. As in, I type the word correctly and it decides “oh, surely you meant this other similarly spelled word” and changes it. Sometimes I don’t notice until after sending the message.

I use MS SwiftKey on my android phone and it will often autocorrect my correctly spelled, correctly used, words, to words that probably don't exist in any language (recently it corrected "blow" to "blpw").

I have French installed on my keyboard as well so sometimes it will randomly correct English words to French words (inconsistently, but at least they're words), but blpw is not a word in either of those languages.

Unfortunately, I think me typing blpw three times has officially added it to my dictionary :)