nils-anders, I investigated a little more and discovered that the modem is non-functional when TLP is installed. Are you perhaps using TLP? If so, that's the likely culprit. If not, there may also be other kernel modules interfering. Check in /lib/modules/4.4.0-36-generic/updates/dkms/ and see.
Clearly this setup is not ready for prime time. Too many things are broken.
nils-anders, I investigated a little more and discovered that the modem is non-functional when TLP is installed. Are you perhaps using TLP? If so, that's the likely culprit. If not, there may also be other kernel modules interfering. Check in /lib/modules/ 4.4.0-36- generic/ updates/ dkms/ and see.
Clearly this setup is not ready for prime time. Too many things are broken.