[NAME]  Under current passive cabling technologies, Thunderbolt 3 at full 40 Gbps can only be sustained along a 0.8m cable — which is why the WD19TB’s cable is so short. (The cable attached to its predecessor the TB16 was even shorter, around 0.5m.) There are active cables that can go out to 2m, but last time I checked they cost around USD $70, and you wouldn’t be able to use them with the WD19TB because the side semi-permanently attached to the dock uses a proprietary connector, so it can’t simply be swapped. I’m not surprised you’re having trouble with extension cables, since you’re likely using passive cables and exceeding the total possible cable length for what you’re trying to run across the cable. But even if you weren’t, a setup involving one or more extension cables doesn’t always perform as well as a single cable of the same total length, because transitioning over a connector is actually a significant source of signal degradation, and even adding a single extension cable creates one additional connector transition in the assembly. (This connector transition degradation is why active TB3 and even HDMI cables have booster chips in the cable in order to amplify the signal just before and/or just after a connector transition.) So unfortunately you’re stuck.
Hello All! Here's my current set upDell Precision 5550 DELL S3422DWG  Monitor LG 27UK650-W 27" 16:9 4K HDR FreeSync IPS WD19TB dock going to Precision with monitors and several USB devices attached. This is working well.  However, what I would like to do is to make it easy to plug the hub into my ALIENWARE M17 R3.  For now I am having to leave the Precision in a spot I can easily get to (would like to hide it away more) so I can manually unplug the dock and then walk over to the M17 to manually plug it into the back (not easiest to get to).  This isn't horrible but was hoping someone might have some suggestions on making this easier. My original plan was to buy a couple Thunderbolt 3 extension cables to put right by the dock and then plug the dock into the extension cable based on which computer I want to power.  However, the cables didn't seem to supply what was necessary to work. Other ideas? Thanks! Mark
WD19TB