After most recent kernel update (4.15.0-44-generic) my tablet freezes whenever plugged into docking station

Same story here, using a XPS 15 99560 and a TB16 dock.

The only solution found for now is to revert to 4.15.0-43, using the Advanced boot options in GRUB.

Link to the kernel changelog. Link to the launchpad discussion where you can follow the evolution.

EDIT : fixed in 4.15.0-45

* External monitors does not work anymore 4.15.0-44 (LP: #1813663)
    - SAUCE: Revert "drm/i915/dp: Send DPCD ON for MST before phy_up"

This problem has been solved in 4.15.0-45-generic. Running these commands can fix the issue:

sudo apt-get update
sudo apt-get dist-upgrade

This kinda happens also to me, with my Surface Pro 3, when I boot it attached to the docking station.

I can boot the device, but as soon as I log in, I get a kernel bug NULL pointer deference error. Which turns the display black and locks up all input. Network is still working though.

If I boot the device and login without docking station, it works. I can attach the docking station afterwards.

I've reported my issue here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1813796