How to make autocorrect/ predictive text work correctly?

Since updating to the new iOS (I installed 17.1.1 and then 17.1.2), the autocorrect features are much, much worse than before. When typing an email or note or text message it often suggests incorrect words or grammar for correct words or grammar.

For instance just now when I wrote "incorrect" a little box showed up saying "in correct". When I tap the box it changes it. I tap the word again and it suggests "incorrecr" which it now autocorrected without a suggestion to "incorrect".

its an absolute nightmare. It doesn't correct obviously incorrect words, like "its" which is a clear error capitalization error at the start of my previous sentence but just now autocorrected "previous" to "precious" without my telling it to, and when I tap on "precious" it suggests "Irecious" (when I tap on "lrecious" it doesn't autocorrect or show a little box next to the word suggesting something else normal like "precious").

How do I fix this function? To be clear it does sometimes correct words correctly.

I read that it's AI learning so it will learn from how I write but it's not learning anything yet over the last 1-2 weeks. It's honestly wrecking my iOS experience.

The other nightmare is that I cannot for the life of me select the portion of text I want to copy. The text selection function has also gotten much worse.

Also while it's not a major problem, the blue underlines are annoying and distracting.