Please teach me. It's driving me crazy.

On my S8 keyboard the configuration menu can be opened using the gear icon appearing in the keyboard. In the configuration menu there should be a bunch of options under "Smart typing" including 'Predictive text' which can be turned off.

This is in the european market, though, I don't know if it's configured differently for different markets.

On google the query "samsung turn off keyboard autocorrect" provides links such as https://www.androidcentral.com/how-turn-and-autocorrect-sams... which may or may not be relevant to you.

Here's the problem. I already turned off all those options long ago, but the annoying behavior remains. To be clear, I don't mind the keyboard predicting things. It's only the retroactive changes that bother me.

Someone else suggested Swift keyboard, so I'm going to give that a try.