Autofill in text messaging adding nonsense strings

My iPhone has just gone crazy adding random words while I'm texting. It goes way beyond normal autofill or the suggestions that pop up. Examples:

I was typing: Must return to work now.

When I hit the wo in work, it added Washington Kristen. It's entirely possible I hit a key other that "O", but inserting (not suggesting) "Washington Kristen"?? I noticed, erased, fixed.

Was typing: Last thing I'd want to do is get you sick.

I didn't notice the change and what it sent was Last thing I'd want to do is get be you a thing.

Perhaps I stumbled on the Y in you. But where does it get inserting an entire nonsense string?

I have to be careful and proof every text message. It's far beyond normal autocorrect/autofill. Not simply a wrong-but-similar-word, but entire phrases added. And these are not suggestions down at the bottom. They are automated insertions. Something has changed in last month or two.

Ideas on how to control this?