Win10 strange multiple monitor issue with 7720 + Dock PR02X

I got my 7720 few days ago, and found a strange issue with multi monitor setup with PR02X. There will be a small unknown monitor that will pop out everytime rebooting the system and i have to manually remove it everytime. Suspected to be the laptop LCD.

In M6700 & M6800, unknown monitor (laptop LCD) appeared too, but once i disconnect it, it will remember the setting and will not active anymore.

I have 3 Docks at 3 locations with different monitors setup. So it is confirmed the strange monitor after disconnected will reappear everytime booting/restart windows. It messed up the main monitor choice, location, orientation, and fonts. After disconnected the unknown monitor, previous correct setting will be automatically reloaded, but the fonts may become weird and i need to logoff & login to make it right again. So much troublesome.

No.1 - Unknown monitor 640x480
No.2 - Main monitor 1440p (DP)
No.3 - Secondary monitor 1080p (HDMI)



Any advice on how to overcome this? Not sure if this happens to TB16 too.

 

Do you have Hyper-V installed/enabled by chance? There is a bug in the Intel GPU driver that presents a "ghost" monitor if Hyper-V is enabled.

 

Hmm no that feature is not installed at all. Optimus is disabled in bios, only discrete GPU is working.

 

With the latest Dell driver for my Intel GPU (older 4th gen HD 4600) I get ghost displays as well. I use an older driver version 20.19.15.4483 which solved that. Maybe you could try an older Intel driver as well.

 

The Intel graphics driver is not involved at all if graphics switching / Optimus is shut off in the BIOS.

 

Sorry, got that "Optimus off" mixed up.

Maybe some dGPU driver version switching can help? Nvidia has quite some versions in different branches available.

 

Hmm, some update on this. Compared among the 3 locations, It seems the problem happened only at the one with KVM. The other 2 locations without KVM, the monitor settings are saved properly I need to adjust only once. Earlier statement was wrong, only 1 location with KVM is messed up. Not yet confirmed, I will bypass the KVM and see if the problem goes away. It is an Aten HDMI KVM.

 

The small 640x480 monitor will only appear if Switchable Graphic is disabled. When enable, it disappeared.