I have a Dell Precision 7760 Laptop with a Dell WD19DCS dock and three Dell monitors:

• Dell U2415 Display DP to Dock DP (1920x1080 Landscape)
• Dell U2415 Display DP to Dock DP (1920x1080 Landscape)
• Dell U3818DW Display USBC to Dock USBC (3840x1600 Landscape main display)

I usually leave the laptop closed and shutdown nightly and boot using the dock button on weekday mornings. I've been using this hardware (and layout) since Jan 2021.

Last week (Jan 12, 2023), after a teams update and reboot, one of the U2415 Displays would not come out of power save mode and windows doesn't see the monitor.

I found that the only way to get all the monitors to work is to open the laptop and keep it open. If I close the laptop, the monitor goes back into power save. The other two external monitors work fine.

The 7760 has two display adapters (Intel & NVIDIA) the only thing I can think of is that either an update was applied to Teams or a policy change was applied that cause a configuration change, but I can't seem to figure out what change cause the monitor to stop working the way it was.

The Display layout looks like this with the laptop open Multiple displays (Extend desktop …):

1 - Dell Precision 7760 Laptop (1920x1080 Landscape)
with Display Adapters (Intel UHD Graphics and NVIDIA T1200 Laptop GPU)
Dell WD19DCS Dock
3 - Dell U2415 Display DP to Dock (1920x1080 Landscape)
4 - Dell U2415 Display DP to Dock (1920x1080 Landscape)
2 - Dell U3818DW Display USB-C to Dock (3840x1600 Landscape main display)

If I close the laptop the layout changes to this:

3 - Dell Precision 7760 Laptop (I'm not sure but this may be the dimmed 3 display)
2 - Dell U2415 Display (was display 3 above)
X - Dell U2415 Display (was display 4 above, but now in power save)
1 - Dell U3818DW Display (was display 2 above, but now display 1)

Could the configuration have changed from using the NVIDIA display adapter to using the Intel Adapter?  I'm not sure how to tell which adapter is in use when the laptop is open or closed.

Any ideas?

Thanks!
Alan

P.S. One change I noticed is that before this problem, all three monitors displayed the DELL logo on booting. Now the two side monitors (the U2415 monitors) display a message on boot about how the monitors support 1920x1080 and that whatever the dock is sending it isn't the right format for the two U2415 monitors).