I have started having issues with my XPS 9365 (13" 2-in-1) and TB 16 dock -- about 20% of the time, when I connect the laptop to the dock, the laptop hangs completely.  Sometimes the video will be frozen still on the laptop, sometimes on the monitor hooked to the dock, sometimes all screens will be blank.  I press the caps lock key and the light no longer responds and I know it's hung. 

I can't tell for sure but it seems to happen when the USB kicks in, since it usually freezes around the time that the USB devices would be detected, maybe 15-30 seconds after plugging it into the laptop (though it also happens without any USB devices plugged into the dock).

 

Based on checking the event log for "system rebooted without cleanly shutting down first", it seems to have started happening in mid-January -- that's roughly when I updated the BIOS for the laptop (2.4.1) and new firmware for the dock (1.0.2).  I have the latest USB drivers as well (1.16.55.1)

 

I called Dell, and after watching the technician change a bunch of irrelevant settings (boot timeout, page file size), he had me try to downgrade the dock firmware back to 1.0.0, but that doesn't work (apparently you can't go back to an older version).  As I've had the dock for more than a year, it's out of warranty, so I've basically been left SOL.  I see a bunch of other threads with recent issues with the TB 16, so I hope this gets sorted out with another firmware or driver update...