I had not noticed this problem before but recently updated to Notes 8.5.3. When I open a new note it has 3 blank lines above my name. Only the first line highlights spelling errors. The second and third seem to have spell check shut off. it looks like this.
wonrg -only this line highlights the error
wonrg - no spelling error highlighted
wonrg - no spelling error highlighted
Phil
This happens every time.
If I happen to cut and paste something into the 2nd or 3rd line I get no spell checking in my note