did you have real ubuntu PC or VMWare Ubuntu?
You can try that first to make sure your module works with the PC
You can also try to install uqmi in your Ubuntu PC, but I don’t quite see I can install it in my Ubuntu 18.
As said before, both MBIM and RMNET mode support QMI protocol
do you mean you don’t want AT command port?
FYI, I saw some other user can compile the MBPL SDK in OpenWRT: