FX on middle speaker

I recently got a middle speaker so I switched to LC+M and noticed that my effects weren’t working on it. I have the effects unmuted and FX returns on so I don’t know why I don’t hear any if they work on my L/R speakers. If anyone has any solutions please let me know.

M is a bus of his own so any channel you want output on it should be routed towards M, also.
What sounds do you hear on the center speaker?