Exhaust flap not working?
 

I drive in M mode probably 90% of the time, so all 4 exhaust pipes theoretically should be working. However, looks like the flap on the right side is not (see pictures taken with M mode on). I tried to nudge the flap with a screw driver just to make sure its not stuck in a closed position and verified that it opens easily and there is a spring holding it shut.

Is this broken or by design?

That can't be right, I would get that checked out. By the looks of the pipes it seems the flap on the passenger side hasnt been opening at all based on how dark the drivers side is. Hopefully be an easy fix

+1 pretty sure they should all be open when M mode is on