Hi,

I'm using TL-MR6400 for backup 4G access everyday and loadbalancing. Working perfectly.... except one thing !

The power supply of the modem-router is on a UPS.
When the grid is off, and the UPS is empty, ... the modem switchs off ; OK :D !

But, when the grid will go back, the modem switchs on and the configuration inside is lost : IP configuration, login/password, bandwidth, APN configuration etc ; everything is lost.

I need to be present on my house, connect to the TP-link wlan, and push the configuration file ... 

NO ! is it a joke ? Have you the same trouble ?

In the other case, just a switch off/switch on without power supply loss, i have not this trouble.