Zyxel 4G router (LTE7240-M403) loose signal when I'm not home

Claudia

Hi all, last year I installed a newly purchased Zyxel 4G router (LTE7240-M403).

It was all ok but starting on last March, the Internet connection is not stable and requires constant reboot of the router. It is a problem for me when I'm out because I have security cameras and other things connected on it…

Is there anything that I can do to configure it properly? 

I tried to connect via telnet and put a reboot.zysh but It don't works…

Thanks to anyone who wants to help me.