Router: Asus a88u.    

When I initially setup the extender it scans and sees my network. It also connects on channel 100 (DFS) . This will work well. However if it loses connection or need to be rebooted it will no longer connect to the network. If I factory reset and reconfig it will again work without issue I'd like to keep the DFS channel due to noise from neighbouring WiFi router operating on non DFS channels. Is there a reason why it will not reconnect after rebooting or power loss