RM500U-CN Doesn't have MBIM mode despite the manual

RM500U-CN Doesn’t have MBIM mode despite the manual.
I’ve modified and install the driver and ttyUSB2 has showed up with the internet working using theses commands.

sudo dhclient -v usb0
sudo udhcpc -i usb0
sudo route add -net usb0

However, I want to use MBIM mode, according to the document, I have to use


But it’s not supported and throws error +CME ERROR: 4 instead. When I use the command to list usbnet it doesn’t show up as supported at all.

+QCFG: "usbnet",(1,3,5) # <-- Here, 2 is missing

My best guess is my RM500U-CN has an outdated firmware, please help.
Is there a way to check the firmware version and/or where to get the latest firmware.

Another thing is the manual said to use Kernel 3.18 and above but my kernel is 6.1.15 which I just compiled myself.

What are your outputs for at+cgpaddr and at+cgdcont? ?

And have you used any other commands other than these to get the internet working?