XPS 9310 Developer Edition not booting when connected to WD19TB dock

[Craig]

With a XPS 9310 Developer Edition laptop (using pre-installed Ubuntu 20.04 from Dell with all updates, including LVFS updates for laptop and dock) is powered off and connected to the WD19TB docking station, it will not boot when I power it on.

When I press the power button (on the laptop or dock) the screen on the laptop becomes active, shows a dell logo, but just stays stuck that way indefinitely.

If I press and hold the power button for 10+ seconds the computer can be forcefully shut down. When I start it up again after forcing it down I then see the Dell logo, but the computer continues where the next screen I see is a GRUB boot menu. From there I can choose "Ubuntu" and the computer boots normally with no problems.

Another way to make everything work is before booting the computer, unplug the Thunderbolt cable from the laptop. Then it boots up normally and I can connect the Thunderbolt cable again and things work normally from there.

I am seeking a solution so I can leave the laptop connected to the docking station and have it boot up normally on the first attempt (no forced shutdowns or having disconnect/reconnect things).

Some details:
OS: Ubuntu 20.04 factory installed from Dell with all updates as of this date.
Kernel: 5.6.0-1034-oem
Laptop: XPS 9310 Developer Edition
Dock: WD19TB

[Craig (craigtlandry)]

Setting target to plymouth based on description here: https://wiki.ubuntu.com/Bugs/FindRightPackage#During_boot

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal:

apport-collect 1906857

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Craig (craigtlandry)]

Marking this as duplicate of https://bugs.launchpad.net/ubuntu/+source/linux-oem-5.6/+bug/1902469 as the fix seen there resolved the issue I was having.