i found the real problem that relates to router reboot "randomly reboot" was from your country network band ,
Tut: 1- go to admin page 2- sign in 3- go to settings 4- go to advanced settings 5- go to Cellular and scroll down 6- select your network manually 7- now in Cellular page the Band region is Automatic by Default Change it to "LTE ALL" 8- reboot your router 9- nothing ;D
