The spell check (red underline) works in some apps but not others.

[AC Question]

My Galaxy s6 Active spell check works for Memos and in Google Docs but not

Gmail. I've been to;
>Language and Inputs
>Samsung keyboard
>Auto check spelling which is switched "ON" and English(US) is also switched "On"

Any suggestion of where else I can look to turn it on?

Thanks, Allan