Conversations involving multiple participants, allowing collaboration and information sharing in Teams
I just tried the following but did not work
Settings >> Disable spell check
Restart Teams.
Settings >> enable spell check
Restart Teams.
Close Teams
Clear Teams cache located in %appdata%\Microsoft\Teams
I ended up navigating to portal.office.com and Teams on the web had a working spell check
Downloaded and installed desktop version, asked me if I wanted to use NEW or CLASSIC, selected classic
Spell check is now working.