@ckillen sorry to hear about the problems – I make the assumption that a sub-module can always lockup, and may need a hard reset/power cycle to bring it back. Internal modem software can only be as good as its tested, sub-modules comms software is complicated and its very difficult to test for all cases.
The Maylfy1.1 now supports a power off capability as well as reset. I treat lab found conditions like you are talking about as a golden opportunity to build in simple reliability – repower, reset. Intermittent field problems are too hard to figure out.
I find it really doesn’t work to give field technicians (or even PhD hydrologist) a training in how to remove a 20pin modem and reinsert it in hot and sweaty field conditions, and also how to have a u.fl antenna stay affixed. “You want what!”
It could also be that the modem power has been turned off, and the device is not working.
I have it such that the modem stream monitor can be enabled from the build command line (or platformio.ini).
I should note it probably is only able to work with the modem UART stream Serial1 running at a slow 9600baud and the SerialTerminal running at faster 115Kbaud
HardwareSerial& modemSerial = Serial1;
// library! https://github.com/vshymanskyy/StreamDebugger
#if defined STREAMDEBUGGER_DBG
StreamDebugger modemDebugger(modemSerial, STANDARD_SERIAL_OUTPUT);
#define modemSerHw modemDebugger
#define modemSerHw modemSerial
#endif // STREAMDEBUGGER_DBG
I haven’t yet tried the SIM7080, still using the Digi LTE modem (I fortunately got enough stock).
In the extreme, last year I used the IP protocol monitor stream debugger WireShark to actually see what was going on the line, and to check for the HTTP response. However this is a pretty difficult setup to get right.