In the Sierra Wireless Android RIL Release Notes we found the following remarks:
MC73xx support multi PDN by default, it needs to switch back to single PDN to work with Android RIL.
Has anybody an idea how to do that? We found nothing about that in the documents we have and in the Internet.
See e.g. https://forum.sierrawireless.com/t/using-the-mc7354-lte-modem-with-qmi/7240/1
You will need the password for the AT!ENTERCND command necessary to enable the AT!UDUSBCOMP command, but you can also find that if you search this forum.
(It is possible to do the change in QMI too, if necessary. I believe the recent Linux QMI SDK might support that. But the AT command version is better documented and therefore recommended.)