Self interference

I’ve got some 900 canopy AP’s close enough together to see each other … how can I tell if I’m causing my own interference?
I have a 6 unit cluster on my main tower w/a CMM and several water towers w/AP’s that are connected to a 5.7 PMP canopy (w/its own CMM) the water tower AP’s are set to receive timing through power port thro a range extender.