Spellcheck in InDesign 2020 build 15.0.2 doesn't work. It acts like it is working, but it never finds any misspellings. I noticed it yesterday when I sent an article to the proof reader and it came back with errors InDesign should have detected. I purposely put in misspellings, but InDesign found no spelling mistakes.
I went back to InDesign 2020 build 15.0 and spellchecking is now working. I've had other serious issues with build 15.0.2. It is very buggy.