Thanks for letting know that the issue is the TB16. I have a XPS15 (9570). All updates installed and still having the same issues. A second dock (D3100) directly on the XPS for mouse and keyboard, resolved the issues (bad workaround, I know)
I think I found a resolution, at least for now.
I went into my power plan settings and changed the USB Selective suspend settings for "Plugged In" to Disabled
Update: nevermind, same issue after a restart
I had tested everything in the post. Bios update, firmware. Drivers. changing the power source charger, setting the selective usb mode to disable, etc. but issue is persistent.
I had tested the usb-c and laptop using Ubuntu Linux OS and the dock and usb works perfectly. So I think it is a windows 10 compatibility issue, with drivers and docking.
Just as a side note, my organization has seen this across a number of laptops and tb16 installations. In addition to my work laptop, I have an XPS 13 9370 (brand new) and a Pluggable TBT3-UDV at home that exhibits the exact same behavior.
I don't believe this is specific to the dock. I was going to install Linux to see if it was the OS or not, but it seems someone beat me to that test. This seems to be either a Dell driver issue, or a Windows HID subsystem issue.
It would be nice to see a fix either way, this is a stupid problem to have in 2019.
Just wanted to throw in my comments about the TB16 after not writing any for 6 months:
We've stopped using the TB16. They all consistently have died or have had what I consider unacceptable amounts of issues for at least 75% of the users in my organization. I've RMA'ed several of them and the replacements end up being just as bad after a few months. I've replaced them all with Caldigit docks which work fine.