Check Spelling While Typing not working in default Apple Apps.

Bartfolkers wrote:

The option Check Spelling While Typing is not working in default Apple Apps like TextEdit, Notes, Mail and Safari. The button under Edit —> Spelling & Grammar —> Check Spelling While Typing looks clickable, but does not work. 

The things I’ve done:

Checkt keyboard text settings• (check spelling automatically).

Safe Mode• : The problem is still present.

Extra Dummy Account• : Problem is not present. 

I’ve installed/deinstalled the application Grammarly a while ago but I’ve deinstalled it according to their instructions (deleted the app in the applications folder). 

MacBook Pro 13″, macOS 11.4

Keep your Mac up to date - Apple Support

https://support.apple.com/guide/mac-help/get-macos-updates-mchlpx1065/mac

See if there is anything here:

Check spelling and grammar on Mac - Apple Support

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS