GSM modem does not work properly (driver / config issue)

[pigs-on-the-swim]

The GSM Modem does not work properly in Network.
There is no IPv6 connection.
Modem is Sierra Wireless, Inc. EM7421
GSM Modem EM7421 works perfect with Xubuntu 21.10 and it works perfect with Ubuntu 21.10. SIM card, APN etc. same as in U21.10 do work fine (same machine Fujitsu E5511).

Need to correct broken settings to get EM7421 properly show and handle IPv6 connections.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: linux-image-5.15.0-25-generic 5.15.0-25.25
ProcVersionSignature: Ubuntu 5.15.0-25.25-generic 5.15.30
Uname: Linux 5.15.0-25-generic x86_64
ApportVersion: 2.20.11-0ubuntu82
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: sysyadmin 1066 F.... pulseaudio
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: XFCE
Date: Sun Apr 24 10:50:46 2022
InstallationDate: Installed on 2022-04-24 (0 days ago)
InstallationMedia: Xubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 (20220419)
MachineType: FUJITSU CLIENT COMPUTING LIMITED LIFEBOOK E5511
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.15.0-25-generic root=UUID=adf3ffda-d8d8-4b33-9786-041e074965c7 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-5.15.0-25-generic N/A
 linux-backports-modules-5.15.0-25-generic N/A
 linux-firmware 20220329.git681281e4-0ubuntu1
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/17/2022
dmi.bios.release: 2.28
dmi.bios.vendor: FUJITSU CLIENT COMPUTING LIMITED
dmi.bios.version: Version 2.28
dmi.board.name: FJNB2E8
dmi.board.vendor: FUJITSU CLIENT COMPUTING LIMITED
dmi.board.version: C3
dmi.chassis.type: 10
dmi.chassis.vendor: FUJITSU CLIENT COMPUTING LIMITED
dmi.chassis.version: LIFEBOOK E5511
dmi.modalias: dmi:bvnFUJITSUCLIENTCOMPUTINGLIMITED:bvrVersion2.28:bd03/17/2022:br2.28:svnFUJITSUCLIENTCOMPUTINGLIMITED:pnLIFEBOOKE5511:pvr10601736746:rvnFUJITSUCLIENTCOMPUTINGLIMITED:rnFJNB2E8:rvrC3:cvnFUJITSUCLIENTCOMPUTINGLIMITED:ct10:cvrLIFEBOOKE5511:skuSK01:
dmi.product.family: LIFEBOOK-FTS
dmi.product.name: LIFEBOOK E5511
dmi.product.sku: SK01
dmi.product.version: 10601736746
dmi.sys.vendor: FUJITSU CLIENT COMPUTING LIMITED

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[pigs-on-the-swim (dw1-4)]

remark:
The issue with the broken GSM-modem-driver did NOT appear during fresh installation (online update during installation was NOT enabled).
The problem kicked in immediately after very first online update (in last state of installation and before very first reboot).

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.