You might want to check this topic as well:
A Humble Librem 5 Daily User Review - Librem / Phones (Librem 5) - Purism community
I am suffering by the same issue. Also in Germany.
I have a Lenovo ThinkPad 250 EUR docking station which does not deliver video signal from Librem 5 to the external monitor.
And I have a 40 EUR dockings station that delivers the video (and I currently use) but suffers from:
- Sometimes the monitor stops getting signal for several seconds. Maybe due to overheating.
- Librem 5 discharges slowly instead of charging while being connected to the docking station which means that it does not get enough juice.
So the correct choice of perfect docking station for Librem 5 is not easy.
The forum user Quarnero (also in Germany) has good experience with AENZR AZ2406. But it seems that it charges the Librem 5 with only 1,5 A, while I would love to find a solution that delivers to Librem 5 up to 3A or as close are possible to up to 3A.