Extreme Networks

I don't have a lot of experience with Extreme networks. I inhereted the support responsibility for a warehouse that used an ancient WiNG controller and AP setup. The APs are 6532s (approx. 20), and the controller is an RFS6000 running WiNG v5.9.  So ...

Randomly it seems that 1/3rd of our AP's have become un-adopted and no longer function. We have found that when restarting the controller, all the AP's reconnect. But a subset of them un-adopt after 20 seconds or so. Perhaps notably the controller is...