Question about Lenovo ThinkPad USB-C Dock 60W (2nd gen.)

In addition to my Lenovo laptop, I also have an HP EliteBook 840 G6 laptop which I would also like to connect via the docking station. Apart from the screen, everything works so far. As far as I have seen, my EliteBook also has the required USB-C Alt. Mode. Does the connection with the screen work at all? When I call up the HP model at Digitec, the docking station appears as an accessory, so it should work somehow. Unfortunately I can't find any helpful info anywhere on how to solve this. I have downloaded the latest driver. But it still doesn't work.