I bought a nr5103e, using with umobile sim card on 5g. Been happily using, until 3 days ago it suddenly stop.

The led on the router shows its connected to internet. Even when login to the control panel, however any of the device connected would not able to ping.

Tried reset and set the apn still the same. Took out the sim card and put in phone. 5g works.
Put maxis sim card in the router, it works.
It just doesnt work with u mobile sim card that it used to work.

Am already at lost. Any expert can advise? Seller suggest to change imei but google fail me on how to change.

U 98, 1000gb, i dont think it makes any difference, been using it around 2-3 month