Why does the Alcatel Link Key IK41V modem not receive a new IP address from the mob. operator Rostelecom?

Question

mobile connection

How can you explain why, when the USB device is rebooted, the Alcatel Link Key IK41V Modem DOES NOT receive the IP address that was issued by the mobile operator Rostelecom? Through experiments, I found out that the Alcatel Link Key IK41V modem with a Beeline SIM card issues a new address upon reboot. In the HUAWEI 3372 modem on the same Rostelecom SIM card, the IP address changes when you reboot or change the network mode, that is, the network is re-registered and a new IP address is issued from the operator.
That is, it is Rostelecom in the Alcatel Link Key IK41V modem that somehow miraculously does not re-register in the network and does not receive a new IP