Your   dynabook Thunderbolt 4 Dock [ Model Part Number: PS0120EA1PRP ] might show one of the below listed issues.

When this happens:

• Monitor connected to the Thunderbolt 4 dock is sometimes not showing any video output, after the PC resume from Modern standby mode
• In case 4 displays are used/active [ quad output mode - 4 displays are shown as active within the Intel Graphics Command Center ], display number 4 is not showing any video after switching from PC only-  to Clone mode
• After resuming from S4 power mode [ Hibernation mode ], where before a Type-C monitor as well as a additional monitor, connected via DP/HDMI port on Video 2 group have been connected to the Thunderbolt 4 dock, the monitor connected to the DP/HDMI port on Video 2 group is rarely disconnecting
• Dual monitor configuration, where both monitors are connected via HDMI, is sometimes causing a flickering/on-off issue on the internal LCD display [ which is gone after approx. 10 minutes and then the display is working normal again ]
• Dual monitor configuration, where the monitors are connected either via DP/Video1 and HDMI/Video2 or DP/Video2 and HDMI/Video2, is sometimes causing a flickering/on-off issue on the internal LCD display [ which is gone after approx. 10 minutes and then the display is working normal again ]
• Dual display output not possible when using the Thunderbolt 4 dock in combination with Portege X40-J series

  Dynabook Thunderbolt 4 Dock Infographic

In order to resolve one or more of the described issues, please apply the below Thunderbolt 4 Dock firmware package v1.0.0.2.

The firmware update tool as well as an instruction- and installation guide can be found below.

 WARNING INSTRUCTION:

         Please read these instructions carefully before applying the Thunderbolt 4 dock firmware update packages.

• Plug the AC adaptor to the dock and connect dock to Computer with Thunderbolt cable. Make sure the dock is detected by the Computer.
• Please make sure the dock remains plugged into the Computer during firmware flashing, disconnecting the dock during flashing may cause dock hardware failure.
• Ensure the PC is in normal working mode during firmware updating. Do not power off or enter sleep mode.
• Please remove any other devices before executing the firmware update [except a monitor, which needs to be connected to DP/HDMI port of the Thunderbolt 4 dock during the firmware update process].

   DYNABOOK THUNDERBOLT 4 DOCK
         Firmware  1.0.0.2   [ TCH1125600A ]

• Change Note:
  The firmware v1.0.0.2 package described in this document is resolving the following potential issues:
  
  1. Monitor connected to the Thunderbolt 4 dock is sometimes not showing any video output, after the PC resume from Modern standby mode
  2. In case 4 displays are used/active [ quad output mode - 4 displays are shown as active within the Intel Graphics Command Center ], display number 4 is not showing any video after switching from PC only-  to Clone mode
  3. After resuming from S4 power mode [ Hibernation mode ], where before a Type-C monitor as well as a additional monitor, connected via DP/HDMI port on Video 2 group have been connected to the Thunderbolt 4 dock, the monitor connected to the DP/HDMI port on Video 2 group is rarely disconnecting
  4. Dual monitor configuration, where both monitors are connected via HDMI, is sometimes causing a flickering/on-off issue on the internal LCD display
  5. Dual monitor configuration, where the monitors are connected either via DP/Video1 and HDMI/Video2 or DP/Video2 and HDMI/Video2, is sometimes causing a flickering/on-off issue on the internal LCD display
  6. Dual display output not possible when using the Thunderbolt 4 dock in combination with Portege X40-J series
     
     
• Firmware Update Tool Info:       
  Dynabook Thunderbolt 4 Dock Firmware Update Tool Version: 1.0.0.2
  
  
• File Download:
  
  
  
• Firmware v1.0.0.2 Update Guide:
  
  
  
   IMPORTANT NOTE:
           Please connect the necessary external display when the firmware update tool is requesting it. In case the display is connected before, the firmware update process may fail.