I can't get dual HDMI monitors to work

Hi -

I just purchased a TBT3-UDZ and cannot get dual HDMI monitors to work. One 1 will work at a time and I have tested that both monitors and HDMI ports on the plugable work independently.

My PC is a HP Spectre x360 i7 10th gen
I’m using HDMI cables between the 2 Dell monitors and the Plugable device.
I’m using the supplied Thunderbird cable between my laptop and Plugable
I have tried both with my HP charger plugged into the laptop and without

Thanks in advance!


Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.

Not all host systems with Thunderbolt 3 support two displays due to possible limitations with how Thunderbolt 3 was implemented on the particular system. It will depend on if the system manufacturer (in your case, HP) has routed two DisplayPort video lines from the system graphics card to the Thunderbolt 3 controller.

Can you tell me what exact Spectre x360 you have? If you’re not sure, see here: https://support.hp.com/us-en/document/c00033108 We’re interested in the product name and product number information.

Please don’t hesitate to let us know of other questions.

Thanks again for contacting Plugable support and best wishes!

Joshua Henry

Senior Engineer | Product Owner
Plugable Technologies

Joshua - Thanks for your response. I have the following PC:

HP Spectre x360 - 15-df1043dx
Product number: 7UT65UA#ABA


Thanks for this information! Doing some research, it appears your system may have trouble supporting dual displays over Thunderbolt 3 from a forum post on the HP support website regarding your model:

"I recently purchased the HP Spectre x360 2 in 1 model 15-DF1043DX. Laptop has 1 Thunderbolt3 port and 1 USB-C port.

I’ve tried 2 differrent TB3 docks (Elgato & Belkin) and neither are capable of displaying to 2 external monitors at the same time."

Unfortunately the replies from the HP reps were functionally useless and provided no real insight or solution to the issue. However, this sounds like the same issue with our dock that the other customer experienced with two other model Thunderbolt 3 docks from other manufacturers. So it would seem to be a system limitation.

You may try our dock over the USB-C port instead of the Thunderbolt 3 port and see if both work (as our dock is backwards compatible with USB-C). However, if they do not there’s likely not much we can do in this situation.

I’m terribly sorry!

Joshua - Thank you so much for your quick response. I tried the USB-C port and it works!!! I can’t believe I didn’t try that already as my USB-C is right next to my Thunderbird port.

Thanks again for all of your help.


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That’s great news, thanks so much for letting me know!

If you ever need anything else we’re always happy to help.


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