External Monitor got disconnect while switching the display

[abhinaychaudhry]

Hi everyone,

I would really appreciate it if someone could help me with this issue. I've spent a lot of time troubleshooting it and haven't been able to find a solution.

I recently purchased a Portronics MPort Vault Pro docking station. Most of its features work correctly, but I'm facing two major issues with my HP ProBook 440 G8.

Issue 1: External monitor doesn't wake after sleep

When my laptop goes to sleep (or remains idle for around 15 minutes), the external monitor does not wake up when I press a key or move the mouse.

• The laptop screen wakes up normally.
• However, the monitor loses its connection over both HDMI and DisplayPort (via DP-to-HDMI adapter).
• The only way to get the monitor working again is to unplug the USB-C cable from the laptop and plug it back in.

---

Issue 2: Monitor disconnects while switching displays

Even when the laptop is not in sleep mode, if I switch displays using Win + P (for example, from the external monitor to the laptop display and then back), the external monitor disconnects.

Again, the only way to restore the display is to reconnect the dock.

Interestingly, when this happens:

• Most USB devices connected to the dock continue to work.
• Occasionally, even the USB-A ports stop responding until the dock is reconnected.

---

Troubleshooting already performed

I have tried almost everything I could think of, including:

• Updating BIOS
• Updating Intel graphics drivers
• Updating USB and chipset drivers
• Updating Windows
• Testing both HDMI and DisplayPort connections
• Reinstalling USB devices and monitor drivers

Unfortunately, none of these steps resolved the issue.

---

Additional observations

I also have access to an HP EliteBook 640 G11.

Using the same MPort Vault Pro dock with the G11:

• Everything works perfectly.
• The monitor wakes correctly after sleep.
• Display switching works normally.
• Monitor brightness can be controlled using DDC/CI.

I also own another USB-C dock (Wozoyo), and it works perfectly with my ProBook 440 G8, including stable monitor connectivity.

So the issue seems to occur only with the combination of the HP ProBook 440 G8 and the MPort Vault Pro dock.

---

Has anyone experienced a similar issue or found a solution?

Could this be related to:

• USB-C DisplayPort Alt Mode implementation?
• HP firmware/BIOS?
• USB power management?
• Intel graphics driver compatibility?

I'd really appreciate any suggestions before I end up buying another docking station, which I'd prefer to avoid.

Thank you in advance for your help!

[Deep_World]

Hi  @abhinaychaudhry 
 
Welcome to the HP Support Community!

Thanks for reaching out!

I Understand your concern on how this must be, especially when you've already tried testing different drivers, settings, docks, and cables and that the problem persists.

Based on your observations, it does appear that the issue is specific to the interaction between the HP ProBook 440 G8 and the docking station, since the same dock works correctly with the HP EliteBook 640 G11 and another USB-C dock functions normally with your ProBook, don’t worry let me help you with this. 

Could you kindly confirm the below detail :  

• The current BIOS version installed on the notebook.
• The Windows version and build number (Press Windows + R, type winver, and press Enter).
• Does the issue occur with a single external monitor only, or have you tested with another monitor as well?
• Have you noticed any entries in Device Manager (such as display adapter disconnects or USB errors) when the monitor disconnects?

In the meantime, kindly try the below steps and confirm if these steps if you have not performed it : 

1. Disable USB Selective Suspend

1. Open Control Panel.
2. Go to Power Options.
3. Select Change plan settings -Change advanced power settings.
4. Expand USB Settings.
5. Set USB Selective Suspend Setting to Disabled for both battery and plugged-in modes.
6. Restart the notebook.

2. Disable USB Power Management

1. Open Device Manager.
2. Expand Universal Serial Bus Controllers.
3. Open each USB Root Hub and Generic USB Hub entry.
4. Under the Power Management tab, uncheck: 
   • "Allow the computer to turn off this device to save power"
5. Click OK and restart the notebook.

3. Perform a Graphics Driver Clean Installation

Even if the driver is current, a clean reinstall may help:

1. Download the latest Intel Graphics driver from the HP support page - https://support.hp.com/  for your specific ProBook model.
2. Uninstall the existing graphics driver from Device Manager.
3. Restart the notebook.
4. Install the HP-certified graphics driver and test again.

4. Check Thunderbolt/USB-C Related Settings in BIOS

Please verify whether your BIOS contains any of the following settings:

• USB-C Power Management
• USB Power Delivery
• Always On USB
• Thunderbolt Security (if available)

5. Run HP Hardware Diagnostics (Link for steps on how to perform the UEFI test - Click here )

Please run:

• USB Port Test
• System Board Test

from HP PC Hardware Diagnostics UEFI and let us know the results.

Additionally, when the issue occurs, please try pressing Windows + Ctrl + Shift + B to reset the graphics driver and let us know whether the external monitor reconnects without unplugging the dock.

I hope this helps. 

[abhinaychaudhry]

Hi @Deep_World,

Thank you for your response and for taking the time to investigate this.

Please find the requested information below:

Laptop: HP ProBook 440 G8

BIOS Version:
BIOS Version: HP T70 Ver. 01.24.03

BIOS Date: 18-May-2026

Windows Version:
Windows 11 Pro Version 25H2, OS Build 26200.8973.

External Monitor Tested:
Lenovo L24-4C

The issue occurs with both:

• HDMI connection through the dock
• DisplayPort Alt Mode (USB-C to HDMI through the dock)

I have also tested another dock (Wozoyo), and it works correctly with the same laptop.

The same MPort Vault Pro dock also works perfectly with an HP EliteBook 640 G11.

Therefore, the issue appears to be specific to the interaction between the HP ProBook 440 G8 and the MPort Vault Pro dock.

• Does the issue occur with a single external monitor only, or have you tested with another monitor as well?
  YES, i have tested with another monitor also.
• Have you noticed any entries in Device Manager (such as display adapter disconnects or USB errors) when the monitor disconnects?
  NO.
  You have asked me to perform some steps below are the responses
• 1. Disable USB Selective Suspend
  I checked the Power Options, but the "USB Selective Suspend" setting is not available. The system uses Modern Standby (S0 Low Power Idle). Running powercfg /a shows only S0 Low Power Idle, Hibernate, and Fast Startup are supported, so Windows does not expose the USB Selective Suspend option.

1. Disable USB Power Management
               I have already tried this not worked for me.
   
               3. Perform a Graphics Driver Clean Installation

                          tried this also.

                        5. Run HP Hardware Diagnostics (Link for steps on how to perform the UEFI test

                         i have run the tests all passed
                         Windows + Ctrl + Shift + B
                          this is also i have tried not working not connected to the monitor again after disconnection

Symptoms

1. After the laptop enters sleep (or remains idle for approximately more than 30sec), the external monitor never reconnects.
2. Switching display modes using Windows + P frequently causes the external monitor to disconnect.
3. The dock remains partially functional (USB devices and sometimes Ethernet continue working), but the display connection is lost until I physically unplug and reconnect the USB-C cable.
4. DDC/CI monitor brightness control works correctly on the HP EliteBook 640 G11 but does not work on the HP ProBook 440 G8 with the same dock and monitor.

Troubleshooting already performed

• Updated BIOS.
• Updated Intel Graphics driver.
• Updated chipset drivers.
• Installed HP Support Assistant updates.
• Updated monitor firmware/settings where applicable.
• Disabled USB Selective Suspend.
• Disabled USB power management.
• Tested different HDMI cables.
• Tested DisplayPort Alt Mode.
• Tested both HDMI and DisplayPort outputs.
• Reinstalled monitor drivers.
• Performed numerous driver reinstallations.
• Verified that the issue does not occur with another USB-C dock.
• Verified that the MPort Vault Pro works correctly on another HP laptop.

i have tried to clean install of window 11 but this is also not working for me.

Could you also please advise if there are any known compatibility issues or firmware limitations between the HP ProBook 440 G8 USB-C/DisplayPort implementation and third-party DisplayLink/DP Alt Mode docking stations such as the MPort Vault Pro?

Any guidance would be greatly appreciated.

Thank you.

Please if you have any experiance or any idea to resolve this kindly help me

[Deep_World]

Hi @abhinaychaudhry 
 

Thanks for your response and thank you for the detailed information and for taking the time to perform all the recommended steps. I completely understand how this must be, especially after updating drivers, BIOS, reinstalling Windows, testing multiple cables, monitors, and docks, and still experiencing the same behaviour.

If the issue only occurs with the MPort Vault Pro dock after all testing, continued use of an alternative HP dock may be the practical workaround.

At this stage, This appears to be a compatibility-related issue between the HP ProBook 440 G8 and the MPort Vault Pro docking station, rather than a failure of the notebook hardware, Windows installation, or graphics drivers.

I would recommend contacting the docking station manufacturer's support team for further assistance and firmware validation, as they are best positioned to investigate potential compatibility or firmware-related limitations with their product. 

I hope this helps.

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Take care, and stay fantastic!