Netgear Nighthawk M5 - WiFi radio shuts off when i plug in an ethernet cable

wifi signal works well but when i plug my laptop into the ethernet port the wifi signal shuts off. Dissappears from my phone's list of available access points. same for my other laptop. when i log into the M5 admin page, everything shows as working fine. 

Using Wifi Analyzer app on my phone i can see the M5's 5ghz network and then watch it vanish when i plug in the ethernet cable.

Other than renaming the wifi network and changing to the 5ghz only option, i have not made any changes. 

To get the Wifi back on i have to unplug the ethernet, restart the router and then it will come back and stay on. If i leave the ethernet cable plugged in, the wifi comes back on then shuts off after about 20-30 seconds.