I've ran into this situation multiple times at my current and previous jobs. I really want to avoid Windows and use something better, but I can't live without two external monitors.
On Windows, it "just works". I don't have to do anything.
On Linux (I tried Linux Mint today) it doesn't work. First, it only connected one of the monitors, the other one did not register. Then I switched to a different cable from the computer to the docking station and it connected both screens - however, they were locked to 30fps. I could not make them work at 60fps (and this is a major dealbreaker, I cannot live with 30fps).
This isn't really a tech support question, I'm more trying to understand what fundamentally causes this situation. Why is Linux still struggling with pretty basic functionality that Windows does with zero setup? Is it the vendor of the laptop and docking station that aren't properly supporting Linux? Or is it some other problem?
I use Linux Mint with 2 4k monitors and have never had a problem. I use an Nvidia card and I think once I installed their drivers it just worked.
I only have integrated graphics, and it may have to do with the docking station as well of course.
You are probably on the right track. Docks have their own limitations on resolution and frequencies, and that might be your chokepoint.
I had a dock for work that only let me do two monitors at 1080 or one at 1440 and the other at 800. They replaced it with a newer dock and now borth are set to 1440.
Well sure yes - but the dock works flawlessly on Windows, so it can't be some inherent hardware limitation.
Hardware isn't the only limitation. The firmware could have less compatibility with linux as well.
Updating the firmware might be a possibility.