Issues with Nighthawk M5 - Disconnecting 4G every few days

HI Folks 

I use my MR5200 for 4G and 5G internet connected to a Tp_link AX1800 Wi-Fi 6 Router. I followed this guild to set it up. 

https://www.youtube.com/watch?v=9t1RJsYymGg&t=68s

It seemd to work, the speed was much better and my smart home devises work seamlessly with the TP-link (was always having isseus with the M5), but for some reason the M5 disconnects from the 4G/5G singnal every 24-48 hours and I need to reset it. When this happens I also cannot use the app to connnect to the M5. 

I have turned the Wi-fi off on the M5 and its connected straigh to the internet port on the router. 

I know the cause of the issue could be many things, i just need to start a process of elimination to fix it totoally.

I have my internet set to dynamic IP. 

The TP-link is set to 192.168.0.1

Is there a log on the M5 that I can acesss, cant seem to see anything on the app. 

Any help would be much appreciated. 

Thanks

B