TP Helix 2nd: how to have Sierra 7345 WWAN-module work?!

[friedrich-eugen]

Hello,
I'm just refurbishing some Helix 2nd, initially to use my spares. After achieving proper installation of Windows 11, I have started to work on a pair of these.
The Helix 2nd 20ch 20cg (M-5<Y71/8GB-Variante) is a still fine machine and if You do not bother to install a heavy workload of software, it stays quick and swift.

After replacing bios-batteries, system-batteries and keyboard batteries, the systems are back and fine again ... I cleaned them out & after installed a M.2 Sata SSD (512GB). Windows 11 is installed, activated, all system go and fine.

But one: Sierra 7345 WWAN

Sierra 7345 WWAN does install properly (it seems) and seems working properly (Gerätemanager / Systems Manager), but Lenovo new diagnosis-tool does tell me,
it does not see a SIM-Card (so it does not test Sierra). WIndows 10 & Windows 11 the like.

Any help or advice?
(I have seen some advice, I do hesitate to follow (using some software for installation, change parts of it to update the firmware (!) of those. cards) and I consider uninstalling all sierra software & updates, than restart from scratch. But that probably would not do the trick?!)

Help and advice would be welcome!!