This may be due to relying on Apple code.
I’ve noticed that if I ask spell check to ignore a word, such as a colloquial misspelling in someone’s dialogue, it seems to work fine (the little red underline goes away).
But if I then view the same doc in Composition Mode, the red line comes back, and I have to go through the same procedure of asking spell check to ignore the word to get the word accepted again.
Can this be fixed?