@BeachHut 

Hi, thanks for posting question here.

When the issue happens, can you get the internet access normally if your clients or phone connected to the router locally? (wireless or via cable)?

If the internet is not available, multiple factors might cause the disconnect automatically. For the LTE disconnecting issue, please try the following steps for troubleshooting:

    1. If the band was changing to a different one when the internet interrupts, select a 4G LTE band(s) manually on Advanced > Network > Internet page and change the Band from "Auto" to "Manual". If your LTE router doesn't support manual band selection, you could get the beta firmware from this thread: Manual Band Selection for 4G WiFi Routers

    2. You may try to change the Network Type on Advanced > Network > Internet page from 4G Preferred to 4G Only.

    3. Please insert the same SIM into another LTE device or even a smartphone to check if the SIM has a problem.

If the LTE connection is fine, only the wireless client devices are unstable while connecting to the router:

    1. Make sure the Router is properly placed, it should be put in an open area instead of inside a cabinet or shelf.

    2. log in to the web management interface of the Router, go to Advanced > Wireless > Wireless Settings, and change the wireless channel to another one.

    3. For 2.4GHz wireless client devices, adjust 2.4GHz channel width into 20MHz, for 5G wireless client devices, adjust 5GHz channel width into 80MHz or 40MHz to avoid interference.