Discretionayr hyphens do not work in DITA ?

I have a bunch of documents done in DITA and FrameMaker 2020 and I have huge amounts of trouble making spellcheck and hyphenation work.

1: discretionary hyphens seems to work exactly opposite of their intention. Rather than help hyphenate words, they make them prevent hyphenation

2: creating personal dictionaries does not seem to work. It is impossible to create a personal dictionary in a self-chosen location and have it work.

3: Adjusting hypenation on single words and making FrameMaker "Learn" does not seem to work either.

I may be missing something absolutely fundamental here,  because these features are quite frustrating. Can anybody help?