XPS13 9380 - resolution messed up when connecting or removing external screen

This my second XPS-13 with the same issue.

My laptop is i7, the one with the high res touch screen.

I connect the laptop to a WD-15 docking station and through this to an external monitor Dell 3417.

If I don't restart the computer after connection, the resolution in the external screen is totally messed up. Huge icons etc.

The same goes in the opposite direction. If I disconnect the external screen with out restart, the resolution in the laptop screen is unreadable.

Is there some kind of work around on this ?

I use Dell laptops with external monitors for too many years and this is the first time -with the XPSs- I experience this.