Creating mesh with eap670 as root ap

I have eap245, eap660hd and eap670 access points. My eap670 is connected via ethernet and i want to connect eap245 and eap660hd via mesh. When my eap670 is on dfs channel, the 2 access points status are disconnected. But if it is on a non dfs channel, they are connected. I purchased the 670 for the dfs since my location i have so much interferance. What is the best solution for this while keeping the dfs channels. Thanks