WWAN-Card not showing up in Fedora 24 based NetworkManager

[P R]

Hello,

while my WWAN-card (Sierra Wireless EM7345) was working under the
default Fedora 23 template I have a problems to get it working under my
fedora 24 templates (all based on the Qubes OS fedora-24-minimal template).

Problem:
the WWAN card is visible within my net-VM, but I can't see it under the
Network Manager applet in the menu bar.

Setup:
WWAN-Card is passed to my sys-net VM via an usb-qube and visible in the
net-VM:

It seems that my WWAN-card is present in my sys-net, but even after
setting up a connection in NetworkManager I can't see a WWAN entry in
the applet of Network Manager like in Fedora23, where I then hit connect
and done.

In my template VM I have also installed ModemManagerwith:
sudo dnf install ModemManager

As suggested in other treads and sites I have run the following commands
in my Net VM

[user@my-sys-net ~]$ sudo systemctl start ModemManager
[user@my-sys-net ~]$ sudo systemctl enable ModemManager

I'm stuck, what am I missing?

- PhR

Some more details regading the WWAN card, attached to my net VM

WWAN-card is present in the VM as USB-device:
[user@my-sys-net ~]$ lsusb
Bus 002 Device 007: ID 1199:a001 Sierra Wireless, Inc.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

All radios are enabled:
[user@my-sys-net ~]$ nmcli g
STATE CONNECTIVITY WIFI-HW WIFI WWAN-HW WWAN
connected full enabled enabled enabled enabled

[user@my-sys-net ~]$ nmcli r
WIFI-HW WIFI WWAN-HW WWAN
enabled enabled enabled enabled

A connection has also been created in Network Manager
[user@my-sys-net ~]$ nmcli c
NAME UUID TYPE DEVICE
Wired connection 1 f19dd69b-8f0c-3f36-aa29-bbd0370b7cd5 802-3-ethernet
enp0s0
T-Mobile(Telekom) 29f32d95-ea6e-46a3-b754-b92283031aaf gsm --

Strangely my WWAN device is in status unmanaged
[user@my-sys-net ~]$ nmcli d
DEVICE TYPE STATE CONNECTION
enp0s0 ethernet connected Wired connection 1
wlp0s1 wifi disconnected --
lo loopback unmanaged --
wwan0 wwan unmanaged --

My loaded kernel modules:

[user@my-sys-net ~]$ nmcli g
STATE CONNECTIVITY WIFI-HW WIFI WWAN-HW WWAN
connected full enabled enabled enabled enabled
[user@my-sys-net ~]$ nmcli n
enabled
[user@my-sys-net ~]$ nmcli e
Error: Object 'e' is unknown, try 'nmcli help'.
[user@my-sys-net ~]$ nmcli r
WIFI-HW WIFI WWAN-HW WWAN
enabled enabled enabled enabled
[user@my-sys-net ~]$ nmcli c
NAME UUID TYPE DEVICE
Wired connection 1 f19dd69b-8f0c-3f36-aa29-bbd0370b7cd5 802-3-ethernet
enp0s0
T-Mobile(Telekom) 29f32d95-ea6e-46a3-b754-b92283031aaf gsm --
[user@my-sys-net ~]$ nmcli d
DEVICE TYPE STATE CONNECTION
enp0s0 ethernet connected Wired connection 1
wlp0s1 wifi disconnected --
lo loopback unmanaged --
wwan0 wwan unmanaged --