(I'm a 20 year software engineer, so plenty comfortable talking about and doing technical things on my laptop.)
I have installed each and every one of the drivers listed in the following post for a Precision 5510 on Windows 10, rebooting between each, and I still get 2-3 TB15 "lockups" per day. In my case, the screens stay on; I just lose USB, sound, and network. Yay!
I also get a notification from Dell Command Update once a week that it needs to update the Thunderbolt Controller to ...250. Which it's done at least 10 times so far, telling me it succeeded each time. Of course, that was one of the manual updates listed above. So something isn't happy.
Before I trouble my IT department to send this TB15 back to Dell, has anyone out there found a fix? Is anyone out there using the TB15 reliably with a Precision 5510 on Windows 10 Pro?