Rebooting and Freezing issue Nighthawk Mr1100 Telstra

My Nighthawk is being used as my main house router with 4g & 5g enabled I am using it without the battery on the charger, even when I first got it and it had 1 device connected to the 5g if a download started it would reboot the router on its own and freeze on booting up, it does it multiple times a day if the internet is being used or not it still happens, I am now running a arlo with it and need a solution to this fix as when I go out the modem reboots and freezes and my cameras go offline.

It doesn’t matter what I do it just keeps happening and it’s really irritating, if anyone haS some Solutions that could fix it I would greatly appreciate it, paid a arm and leg for a modem that does this has really annoyed me.