uHUB H6+ 6-in-2 USB 3.0 Hub for Surface Pro with Dual Monitor and Dual Card Reader

Go through the following:
1. Press the Windows Key plus R, type "devmgmt.msc", and press Enter.
2. In Device Manager, under the appropriate heading, confirm that your expansion card is listed and that there isn't an exclamation mark next to it. For example, a USB controller card would be under Universal Serial Bus controllers.
3. Your USB device is listed according to the name of the chipset or the dedicated name.

Go through the following:
1. Click the Apple icon.
2. Click About This Mac.
3. Click More Info or System Report.
4. Under the appropriate heading, please check that your USB device is listed (according to the name of the chipset or the dedicated name) and that there isn't an error. For example, a network card would be under Ethernet Cards.
5. You may have to refresh the System Information page after you plug in your device. To do so, press Command + R with the System Information page open.

It is likely that Windows has automatically turned off the USB Root hub to save power and caused the issue.
The steps below instruct how to configure the USB root hub to stay on during the sleep mode of the upstream computer, to prevent this from happening.
Windows 10 / 8
On your keyboard, press the Windows Key plus X and select Control Panel.
Click Hardware and Sound, then click Power Options.
Click Change plan settings for the plan you want to change.
Click Change advanced power settings.
Click the plus sign (+) next to “USB settings” and “USB selective suspend setting” to expand the options and change the setting to Disabled.
Click OK to apply the setting.
Note: You may need to disconnect and re-connect your USB hub after applying these settings to re-establish the connection.
Windows 7 / Vista
Click the Start button and select Control Panel.
Click Hardware and Sound, then click Power Options.
Click Change plan settings for the plan you want to change.
Click Change advanced power settings.
Click the plus sign (+) next to “USB settings” and “USB selective suspend setting” to expand the options and change the setting to Disabled.
Click OK to apply the setting.
Note: You may need to disconnect and re-connect your USB hub after applying these settings in order to re-establish the connection.
Windows XP
On your desktop, right-click the My Computer icon and select Properties.
Click the Device Manager tab.
Expand Universal Serial Bus controllers by clicking the arrow to the left of it.
Right-click the first USB Root Hub device and select Properties.
Click the Power Management tab.
Clear the box next to Allow the computer to turn off this device to save power.
Click OK to apply the setting.
Repeat steps 4-7 for any remaining devices in the Universal Serial Bus Controllers section with “Root Hub” in the name.
Note: You may need to disconnect and re-connect your USB hub after applying these settings to re-establish the connection.

We suggest you to rearrange the monitors in Windows to match the physical location of them on your desk. 
Go through the following:
Windows 10 / 8
1. Press the Windows Key plus X and select Control Panel.
2. Click Appearance and Personalization, then click Display.
3. Click the Resolution or Adjust Resolution option from the left column, which will display your monitors as numbered icons.
4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
5. Click and drag the monitor icons to best match the physical location of monitors.
6. Click OK to apply the changes and close the window.
Windows 7 / Vista
1. Click the Start button and select Control Panel.
2. Click Appearance and Personalization, then click Display.
3. Click the Resolution or Adjust Resolution option from the left column, which will display your monitors as numbered icons.
4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
5. Click and drag the monitor icons to best match your physical setup.
6. Click OK to apply the changes and close the window.
Windows XP
1. Click the Start button and select Control Panel.
2. Double-click Display.
3. Click the Settings tab, which will display your monitors as numbered icons.
4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
5. Click and drag the monitor icons to best match your physical setup.
6. Click OK to apply the changes and close the window.

Go through the following:
Windows 10 / 8
1. Press the Windows Key plus X and select Control Panel.
2. Click Appearance and Personalization, then click Display.
3. Click the Resolution or Adjust Resolution option from the left column.
4. Expand the drop-down menu next to “Multiple displays” and select Duplicate these Displays.
5. Click OK to apply the changes and close the window.
Windows 7 / Vista
1. Click the Start button and select Control Panel.
2. Click Appearance and Personalization, then click Display.
3. Click the Resolution or Adjust Resolution option from the left column.
4. Expand the drop-down menu next to “Multiple displays” and select Duplicate these Displays.
5. Click OK to apply the changes and close the window.
Windows XP
1. Click the Start button and select Control Panel.
2. Double-click Display.
3. Click the Settings tab.
4. Un-check the box beside Extend my Windows desktop onto this monitor.
5. Click OK to apply the changes and close the window.

MacBook and Mac Mini using the Apple Silicon chip support only one single external display over the Thunderbolt 3 ports, even when connected to a Thunderbolt 3 hub or adapter with multiple video output. Turning off the laptop display or using clamshell mode does not change this.
Using a USB-C DisplayLink-based hub or video adapter may be an option to allow more than one external display with an Apple M1-based Mac device.
Note: this limitation does not affect Intel-based Macs with Thunderbolt 3.