Soon to be released new Dell Docks may require BIOS and driver updates on your laptop before use!

I don't have the TB15 yet, but I have had an issue with the P2715Q monitor.  I had to exchange it for a hardware ver 3.  The monitor would blink a lot with the XPS15 lid closed.  I haven't yet tried the new monitor with the XPS15 lid closed.  I'm not looking forward to being disappointed.

I have a XPS 9350 XPS 13 and have the exact same issue. It got a lot better with the ASUS USB root hub driver, but I still get the TB15 light going out and nothing on it works except the power. I found that I have to not only unplug and replug, but I have to cycle power on the TB15 dock. Any tips appreciated... I don't feel like this is a $300 product, that's for sure.

I am having the same issues that everyone is describing without the dock. I have a monitor hooked up to the USB/Thunderbolt port and it constantly disconnects. I just bought this new $2200 laptop and a Dell $800 Ultrawide Monitor and they can't be used together. They used to work together until I applied the latest TB firmware and bios. One of those broke this laptop.

thanks for pointing that out. I just tried it (well both since it shows up twice even though the files are the same). When I tried to apply it it says its already up to date. Why does dell list it twice and why are they still old updates showing a new release date?

FYI, the Thunderbolt 3 firmware was once again updated today.  I already sent my TB15 back.  I would be interested to know if this fixes its issues.  

Where did you find it?

The Dell "Drivers & Downloads" page shows a "Last Updated" date of today (BTW, what does it mean?, I find it extremely confusing) but the "Release Date" and the file itself are still the old ones.

I had that happen before in trying to update with new release. I went into Programs and Features and uninstalled the old version and then the new update was able to install properly. The fact that this release is marked "urgent" may mean this might fix some problems. (I'm still waiting on my 2nd TB15 dock)

I think I may have been in error - it was the Intel Thunderbolt Controller Driver that I had previously uninstalled and reinstalled with new version. I don't think you can uninstall the Thunderbolt 3 Firmware Update and then reinstall. Perhaps Tech Support could walk you through process of properly updating the Firmware.

I had that happen before in trying to update with new release. I went into Programs and Features and uninstalled the old version and then the new update was able to install properly. The fact that this release is marked "urgent" may mean this might fix some problems. (I'm still waiting on my 2nd TB15 dock)

Not sure about it saying the driver is already up to date. There is typically an initial release date listed and then when they update the driver the most recent update date is displayed. At least that is how I interpreted it.

I gave up on the TB15 for now and I have been using the Visiontek USB-c to DisplayPort 1.2 adapter to get the 3840x2160@60hz on the P2715Q.  I still had intermittent flickering on the 9550 with the latest Dell provided Intel HD/nVidia 960m drivers on their support website last night. I let the nVidia control panel update to the latest nVidia drivers and smooth sailing so far today.  We'll see if it lasts...

I am curious as well if this just means the page was updated with more information and not the driver.  Several of the drivers have an updated/recent modified time but when I check the file name and size they are identical to what I've downloaded for the release date.

Stability with the most recent Thunderbolt 3 Firmware update (release 2/16) is much better.  In the last 5 hours I've only had 1 computer lockup and 3 disconnects from my Ethernet.  HUGE IMPROVEMENT! 

Not 100% yet. 

I don't believe there was a new Thunderbolt firmware released today. Version is still 2.11.06,A02 from February 4th and (with two external 4K monitors) it's unstable as ***. Simply unusable.

I'm giving up... today the TB15 is going back. And honestly, I wish I could return the XPS15 as well: after this ordeal I don't think I'm ever going to enjoy my laptop again.

Earlier today, I installed all of the re-released driver updates in the recommended order, restarting btwn each of them.  I am at over 4 hours of uninterrupted ethernet connection.  Everything else seems to be working.  I do have my keyboard/mouse receiver plugged into laptop rather than the dock.  I am afraid to change anything.  Would rather have in the dock.  I still cannot turn computer off.  Restarts even when i ask to power off.

Stability with the most recent Thunderbolt 3 Firmware update (release 2/16) is much better.  In the last 5 hours I've only had 1 computer lockup and 3 disconnects from my Ethernet.  HUGE IMPROVEMENT!  Not 100% yet.

When you installed the Thunderbolt Firmware update (File size is only 501KB) did it take a very short time - i.e. the screen says "Preparing Thunderbolt Firmware Update" and the blue progress bar goes a short distance and then cuts out and the message: "Thunderbolt Firmware is up to date" in a popup appears on the screen? Just want to make sure I'm doing it right. It just takes a few seconds.