IOS 14. It's unusable in my iPad. I choose a suggested word but it has a mind of its own. And the changes are often ridiculous. However, on my iPhone, it works reasonably well. Why the different experience?
iOS 14 autocorrect in general has been very poor for me. Literally changing comments correctly spelled words to something random. I believe iOS uses a combination of general machine learning generating from the total user base of all iOS users which is then pushed in iOS updates and on-device learning, which could explain the variation.