Yes it has public ip.
As you can see the interface MODEM_2_1_4 has the public IP.
Checked it is belongs to the operator.
Just that I can't confirm if the operator blocked anything,
My open port is greater than 10000.
If the modem IP is not a public IP, port forwarding cannot be accessed from the Internet, since there is a NAT in the modem's superior (operator network), this public IP host by operator.
Regarding the op version, the reason that GL firmware is based on the Qualcomm SDK (QSDK) to develop, and the op version provided by the IPQ50xx QSDK is 19.07.8. We will submit this expectation to Qualcomm.