LM1200 repeatedly dropping link

I'm having the exact same issue and working through it now with support... my modem will randomly go through instances of the network connection repeatedly cycling (every 30s or so). I'm on verizon. The disconnect for each cycle seems to follow a instantaneous status change to the cell signal light, which may sometimes flash red a single time at the start of each cycle. When this was connected to a router with more detailed logging, the WAN gateway would flip / flop with each cycle. I have ruled out issues like the specific PC / router connected to the device, network cables, physical location of modem (different cities), etc. The problem is likely either 1) the unit is switching between cell sources, such as 3G vs LTE, and it's causing the modem to reset the network adapter or 2) the service provider verizon is sometimes switching between IPV4 and IPV6 and the modem / downstream devices aren't digesting it well.

It could also be a combination of the two factors above. I'm not savvy enough to force these external states upon the modem to narrow it down further, but I've mostly ruled out everything under my control on the device / network side. 

If I'm able to catch another wave of resets with everything ready to go, I'm going to try to switch the Network Mode from Auto to LTE (to elimate its ability to switch between LTE and 3G) and also try setting the default PDP from IPV4V6 to just IPV4.