Nighthawk M2

I’m using my M2 as my main WiFi provider with a local sim. Wanting to use it for wireless and Ethernet connections to run my very small scale smart home, ie smart tv, Alexa and Philips smart lighting.
I have a gs205 switch for this reason but every time I connect via Ethernet cable the WiFi drops off.. I’ve disabled the timeout it’s set to charge+tether.. Anyone have any ideas or advise, also I’m considering getting a mesh set up to get better coverage but still running off my M2.. If there are better options please do tell. FYI mobile data is my only option in my location… Thanks