Description of problem:
In NetowrkManager-ci, we are using gsm_sim.pl script to simulate modem. That does not work with new gnome-control-center panel. When pressing the switch to turn "Mobile Network" on, the APN list shows up, we can create new APN, but it can not be activated.

Version-Release number of selected component (if applicable):
gnome-control-center-40.0-16.el9_b.1.x86_64
ModemManager-1.18.0-1.el9.x86_64

How reproducible:
always

Steps to Reproduce:
1. clone NetworkManager-ci repo: https://gitlab.freedesktop.org/NetworkManager/NetworkManager-ci.git
2. bash prepare/gsm_sim.sh modemu
3. try to activate modem in gnome-control-center

Actual results:
NetworkManager connection for APN is created, but can not be activated.

Expected results:
Connection should activate.

Additional info:
Connection can not be deactivated as well, if activated using "nmcli".
Connection can be activated with some physical modems.