Erroneous Spelling Checks

Can anyone tell me why in the Classic Editor I keep getting erroneous items being flagged as spelling Mistakes?

When you move the cursor out of the editing field many words have a red underline as being misspelled but then you go to correct it and the word was correct all along. This was not happening when I was using Disable GutenBerg but I had to stop using that plugin as it was not compatible with Rank Math. Now I am using the Classic Editor plugin.

It’s getting to be very distracting.