Hello all,

since a couple of years my sister's TL-MR6400 loses from time to time the 4G connection, showing this message in the admin panel:

Internet Status: 

Unknown failure reason. Please make sure your configuration is correct.

To fix it we have to reboot the device (sometimes twice).

The SIM card is perfectly fine.

Do you have a suggestion? In the "Firmware upgrade" section, no online upgrades are available, but in the tplink website I could find "Archer MR6400(EU)_V3_20190730".
I am afraid to use it since it seems for a different model.

Could you please help?

Cheers,

TonyStark