Modified imei invalid

Routers 4G LTE, 5G NR, USB modems
1

I modified imei in the settings interface and used the at command:

AT+EGMR=1,7,“358698093561980”, the modification is successful, the router interface displays the new imei, but the device imei displayed on the T-Mobile plan page is still old, this is very strange

2

Isn’t the plan tied to the IMEI? Like … will it even change then?

3

Usually after I change the device, I will also see the change in the device on the T-Mobile website