In our setup, MAX HD2 is located on rural area and about 300 km away. We found out that BR1 radio SIM module may freeze in certain conditions when operator changes something on their side and 3G/4G connectivity fluctuates. Despite that SIM module restarts itself when connectivity is lost in these conditions, the connectivity may not be restored automatically.
Today we just drive 600 km for re-connecting power cable, I think there should be some other way to overcome such freezing. For example, adding a cold restart watchdog function that activates only after predetermined soft restart cycles fails and reboots a whole device to bring the unit back online.
Of course, we can consider to install a separate remote power cycling solution, but it is not so easy to implement due to limited space on tower and this may add an extra point of failure instead.