Spellcheck on iPad / iOS | How does it work?

I have the “Check spelling” preference set to On in Drafts’ Editing prefs on my iPad. But no misspellings are ever highlighted on Drafts on my iPad. When I open the same drafts on my Mac, the red dashed spellcheck underline appears on words of suspected misspellings. How can I have misspellings on iPad and iPhone show with emphasis under misspelled words?

First of all, have you read this thread?

No I hadn’t read that (no common search terms it the title with mine).
I have now. And I didn’t see any usable insights. One said spellcheck should work, another said that it’s not working on their setup.
Should spellcheck work on iPad? Is there a way to get it working?

Any chance you are using a different keyboard like that user was?