Problem Driving Two Monitors with Thunterbolt 4 Dock

[falagan]

Hi everyone,

I've bought a ugreen Revodok Max 208 (U708 / 25053EU) Thunderbolt 4 dock. It is listed in the manufacturer's page as able to support dual 4K 60Hz monitors over Thunderbolt 4 or Thunderbolt 3. The thing is, when I connect it to my HP Omen (15-EK0004NS) Thunderbolt 3 + DisplayPort 1.4 port, and my two 1440p monitors (one is 100Hz, the other one 144Hz) through two of Ugreen's Thunderbolt 3 to HDMI cables, also listed as supporting 4K 60Hz, only the first monitor to be plugged in is recognised.

I have looked at the Thunderbolt control panel, and the dock is correctly iddentified and connected. I have tried to lower my display adapter settings to 1080p 60Hz (and lower, though this *should* be supported due to the hub's specs) in the one recognised display, in case it was a bandwidth issue, but still I had no luck. The second display does not even show up in the device manager, nor is it recognised by windows. That is, until the main display is unplugged, then the second one comes to life.

I have tried reinstalling all available drivers and the usual troubleshooting (the dock does not have specific drivers in Ugreen's page) but am still unable to solve the problem. I even tried the RMEnablePhyRepeater thing, to no avail.

Any help diagnosing the issue would be greatly appreciated.

[Nal_NR]

Hi @falagan,

Welcome to the HP Support Community. 

I'd be glad to help you! 

I understand how frustrating it must be to invest in a Thunderbolt dock and cables only to find that it doesn’t work as expected with dual monitors. Let’s work together to identify the cause and get this resolved.

• Have you checked if the monitors work correctly when connected directly to the laptop without the dock?
• Are both monitors using identical Thunderbolt 3 to HDMI cables, or are there differences in their connection setup?
• Have you tried connecting a different brand/model of Thunderbolt dock to verify if the issue is specific to the Ugreen Revodok Max 208?

Test Each Monitor and Cable Independently:

• Connect each monitor directly to the laptop’s Thunderbolt 3/DisplayPort 1.4 port (one at a time) to verify that both monitors and cables are functional.
• If one of the monitors or cables has issues, it could be causing the dock not to detect the second monitor.

Check Dock Firmware Updates:

• Visit Ugreen’s support page to see if a firmware update is available for the Revodok Max 208 dock. Firmware updates can fix compatibility and bandwidth allocation issues.

Adjust Display Settings for Each Monitor:

• Connect only one monitor through the dock, then open Display Settings.
• Manually adjust the refresh rate and resolution to something more modest (e.g., 1080p @ 60Hz).
• Once the first monitor is stable, connect the second monitor and see if it appears.

Test Different Port and Connection Orders:

• Connect the monitors to different Thunderbolt ports on the dock to rule out a defective port.
• Also, reverse the order in which the monitors are connected to see if the issue persists.

Verify Laptop's Thunderbolt Bandwidth Allocation:

• Use the Thunderbolt Control Center on your laptop to check bandwidth usage.
• Some laptops limit Thunderbolt 3 bandwidth or allocate resources inefficiently when using multiple high-resolution displays.

If the problem continues, consider testing the dock on a different Thunderbolt-enabled laptop to rule out issues with the dock itself. Alternatively, use a different brand of Thunderbolt dock certified for dual-display setups with your specific laptop model.

Keep me posted for further assistance

Please mark this post as “Accepted Solution” if the issue is resolved and if you feel this reply was helpful click “Yes”.

[falagan]

Hi @Elohi_NR,

Tanks in advance for your assistance, I'll reply the questions one by one:

1. Yes I have, and they both work. Actually, the monitors work correctly even through the dock, just that only one works. If I unplug the working one, the other one comes to life. Once I plug it back in, though, it does not turn on, until the one that is on is unplugged.

2. Yes, they are, exactly the same model cable. Again, there is no difference made between the two monitors (except maybe which one works if the dock is turned on with both plugged in), so it does not seem like a faulty cable.

3. Unfortunately, I do not have more Thunderbolt docks at my disposal. I tried a regular, non-Thunderbolt USB dock (Ugreen Revodok Pro 209) and it does work, just not keeping up with my displays' maximum refresh rate (which is to be expected for  dual 1440p displays).

I tested both monitors individually, both plugged in directly into the computer, and through the dock. No issues either way.

Ugreen's page does not offer drivers for the 208. It does have them for other models, just not the 208. Microsoft's page says there are no Thunderbolt drivers needed for Windows 11 as they come with the OS. I guess it is these drivers that are being used?

I did lower both monitors' settings to 1080p 60Hz, as at first I suspected it may have been a bandwidth issue. Nothing changed, only one monitor worked at a time still.

I tried all possible combinations of plugging the two monitors into the three thunderbolt ports at the back of the dock. Had no luck, the behavior did not change.

Not sure where the bandwidth allocation can be seen in the Thunderbolt Control Panel. HWiNFO64 tells me PCI Express is version 3, current link width is x4, and current link speed is 8GT/s. I believe this means it is all running fine, but am not well versed in these technical aspects.

Thank you very much for taking the time, please, any gaps I can fill in, you just ask.

[Nal_NR]

Hi @falagan ,

Thank you for performing the recommended steps.

We apologize for the inconvenience. The issue seems to persist even after attempting the troubleshooting steps mentioned above.

This might require one-on-one interaction via remote assistance to fix the issue. 

I've sent you a private message with further instructions. In order to access your private messages, click the private message icon on the upper right corner of your HP Support Community profile, next to your profile Name or simply click on this link.

If the information I've provided was helpful, give us some reinforcement by clicking the Accepted Solution button, that'll help us and others see that we've got the answers!