XPS15 & D600 combination = shaky mouse cursor

The XPS 15 has both an integrated and discrete GPU, whereas the XPS 13 only has one, so that somehow might be responsible for the anomalous behavior here.  Have you gotten the latest DisplayLink drivers direct from DisplayLink rather than Dell?

Just as a general note though, if you only need to use XPS 15 and XPS 13 models that all have USB-C/TB3 ports, you should really consider using the TB16 dock rather than the D6000.  The D6000 as I hinted at just now uses DisplayLink technology rather than tapping into native GPU outputs.  That introduces a large number of drawbacks, many of which I described in this post, but there are two more drawbacks to the D6000 that would apply specifically to the XPS 15:

- Due to a Windows limitation, on systems that have multiple GPUs (like the XPS 15), only the primary GPU can be used for content being shown on DisplayLink-driven displays -- and in that system the Intel GPU would be considered primary with no way to configure it otherwise.  That means that you will never get any use out of your NVIDIA GPU for anything being displayed on dock displays.

- The D6000 can only supply 60W of power to attached systems for charging.  The XPS 15 models are all designed for 130W, so you'll either need to connect the AC adapter in addition to the D6000, or else put up with significant performance throttling when your system is under heavy load, and much slower battery recharge times.  By comparison, the TB16 is able to supply up to the required 130W over its docking cable, as long as the TB16 itself is powered by a 240W adapter.  The TB16 can be ordered with a 180W or 240W adapter, so you'd need the latter.

The D6000 is meant mostly for use cases where you'll be using it with multiple different systems, some of which have USB-C ports and some of which only have USB-A ports.  This is particularly true for businesses that use "hotel desks" (nobody has assigned seating) and where they might have a mixture of newer USB-C systems and older systems that don't have that connector.  For them, the standardization benefit of the D6000 is enticing.  For others, it's really not a great choice.

(Note: There is also a WD15 dock that delivers all of the benefits over the D6000 I just described, as long as you get the 180W version rather than the 130W version for that model if you'll be using it with an XPS 15, but since the WD15 uses regular USB-C rather than Thunderbolt 3, it has much less display bandwidth and therefore would not be able to drive a 3440x1440 display.  The WD15 can do dual displays up to 1080p or a single display up to 2560x1600.  The TB16 can do dual 4K displays and some triple display configurations.)

So I had the same issue with Dell Latitude 500 and D6000 dock. The solution for me was to change the hertz in my external monitor from 60 to 50. For some reason, the mouse wiggles on 60. 

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