Thanks for posting here! The Plugable UGA-2K-A is a high powered USB 2.0 device which needs close to the 500mA (max bus power that can be drawn by a device as per USB 2.0 specifications) for powering up and functioning.
Two possible reasons why the Plugable UGA-2K-A is not powering up when connected through the powered Hub -:
There are other devices plugged into the hub are collectively already drawing almost the total power that can be supplied by the hub. Hence, the hub cannot provide the required power to power up the Plugable UGA-2K-A.
If there are no other devices plugged into the hub and the hub is still not able to provide the required power to power up the Plugable UGA-2K-A, then either the power adapter of the hub or the hub itself has failed.
We always recommend plugging any of our USB Graphics Adapters either directly into an inbuilt USB port on the system, or through a powered Hub which is capable of providing 500mA or power per port (like our Plugable 7-Port USB 2.0 Hub With 3A Power Adapter)
Hope the above information helps! If you need any additional information, feel free to post back here or shoot us an email at firstname.lastname@example.org. We are here to help!