Conversations involving multiple participants, allowing collaboration and information sharing in Teams
Hello Chad_Albrecht_999! My name is Jeremy and I’m happy to help you with your question.
I found a more recent thread as well that had similar information.
Try these steps in order:
Log in to Teams > Turn Spell Check Off > Restart Teams > Turn Spell Check On > Restart Teams again.
The thread you linked as well as the one that I found are both from 2022. The one I found being from June/July so it doesn't seem to be a common issue any longer.
I hope the steps I gave are able to make the spell check work again.
Regards,