@MiChatz  What is the exact behavior you are seeing when you say that it "can not boot"?  Do the internal display and external displays all just stay black and you never even see the Dell logo that normally appears right at startup?  Does it get to some point and THEN go black?  If the latter, does disconnecting the dock allow the system to function as normal at that point even though it didn't boot as expected initially?  The more descriptive you can be in your problem report, the more likely people here will be able to help you.

Have you updated the TB16's firmware?

Power up your Dell and press [F2] to enter the UEFI BIOS you should be able to change your Thubderbolt configuration to have No Additional Thunderbolt Security and also to allow Boot Support.

Check Enable USB Boot Support, Enable External USB Ports, Enable Thunderbolt Ports, Enable Thunderbolt Boot Support, Always Allow Dell Docks, Enable Thunderbolt (and PCIe behind TBT) pre-boot modules and change Security Level - No Security. Then apply the settings and reestart.

@Philip_Yip  Unfortunately, those settings didn't solve my issue. 

@jphughan 

The system stops at the point that shows the Dell logo and the spinner.

It stays there and the system never boots.

All of the screens working and showing the same picture.

If I unplug the Dock there will not be any change. After that, the laptop needs a force shutdown.

In case of plugging the dock after the boot, everything is working as expected.

HDMI, VGA, sound, charging. Even the power button of the dock.

@jphughan 

I don't have updated the TB16 firmware and TB3 controller drivers since I don't have Windows.

I am trying to find a solution for that. Do you think that will solve my issue?

 Thank in advance for your time.

@MiChatzWhile the settings suggested above are fine to use for testing, I would strongly recommend setting them back to defaults, i.e. no Thunderbolt boot support and Security Level 1 "User Authorization".  Enabling boot support and especially disabling all Thunderbolt security is not a safe way to run.

If you're getting to the point where you see the spinning dots, then it means the OS is loading, which means this might be an issue that only affects Linux.  You also didn't answer my previous question as to whether you'd updated the TB16 firmware.  And for that matter did you update the TB3 controller firmware in your system?  That is NOT part of the system BIOS update.

@MiChatz  I'm not sure whether it will solve your issue since I haven't looked through the release notes of all versions of those firmware updates to see what's been fixed, although even if I were to do that, sometimes fixes are incorporated into updates without being listed in release notes.  It's unfortunate that those updates are only available when running on Windows, and in fact the TB16 firmware update can only be run from a supported system because it actually executes during boot time sort of like a BIOS update.  The XPS 13 9350 is a supported system, but you would NOT be able to just connect any random Windows system that had Thunderbolt 3 and run the TB16 firmware update that way.  And full Windows doesn't support being booted from a USB device.

For what it's worth, Dell did fix this with the TB16's replacement, the Dell WD19TB.  It supports firmware updates from Linux.  Not sure about the TB3 controller firmware on newer systems.

Hi,

Was there a viable fix for this?

I am experiencing it with my dell and it is driving me nuts.

Cheers

Are you using a wireless mouse or keyboard and the USB receiver is plugged into the dock? Try removing it and insert into laptop instead?

@jphughan,

I am very interested in your post, being a XPS13 9560 Linux user, whose been trying for ages to work out how to update my TB16 firmware.

Are you saying that the Firmware Update Utility does more than just update firmware on the TB16, and that it updates something on the laptop as well? If so, does that imply that an updated TB16 cannot be used as a docking station for any laptop with a Thunderbolt 3 port, but only for laptops that have had the Dell TB16 firmware update run on the laptop?  Is there no other way of making the necessary updates on a DELL laptop running Linux?

Thanks and regards