My first thought would be to raise the M80s and see if that helps. This assumes voices are split between mains and center, which I think is a safe assumption but I'm not 100% sure.
The advantage of raising mains rather than center is that the mains don't get in the way of the screen
Other option obviously would be to put the center above the TV rather than below (I've seen that more than a few times) but you already have a stand for the center...
Yes you're too close to the screen but hopefully that just means you need more drastic speaker adjustments to get voices coming out of the correct body parts.
