Windows 10 Multiple 4K Displays - All Windows Move To Primary Monitor On Resume BUT ONLY When Text Scaling Not Set To 100%

Question

I've got a really odd problem that I can't seem to get to the bottom of. Here's the setup:

• Dell XPS 13 9380
  • Intel UHD Graphics 620
  • Windows 10 18363.592
• Dell WD19TB Dock
  • XPS 13 connected via Thunderbolt port
• 2 x LG 27UL600
  • #1 connected to WD19TB USB-C/DisplayPort with USB-C to DisplayPort cable
  • #2 connected to WD19TB Thunderbolt port with USB-C to DisplayPort cable
  • Both running 3480 x 2160 @ 59Hz with display scaling of 150%

The problem:

When the system is put to sleep, upon resume, all of the windows move themselves onto the primary display. This is incredibly annoying.

My initial thoughts...

Were that the displays weren't waking up quickly enough or disconnecting during the sleep/resume cycle - I've tried a few things based on research of other's similar issues such as deleting registry keys etc but nothing made a difference.

A curious revelation:

When I change the display scaling to 100%, everything works perfectly, the displays resume, and the windows are where I left them!

Obviously keeping the scaling at 100% isn't practical on a 27" 4K monitor, so does anybody have any ideas? Why is scaling to 150% causing this to happen upon resume?

NB. The previous setup was 3 x 1080p, DisplayPort/DisplayPort/HDMI - all working perfectly until the monitor upgrade. And for the record all firmware/drivers etc are up to date and installed correctly.

Answer 1

The problem you are seeing is a "Feature" of Windows introduced a good while back without a way to effectively turn it off. Certain monitors (Especially TVs) when in sleep or off will report (lack of report) back to the PC that they are, in fact, off/disconnected. Windows then does it's "feature" of moving all applications from the 'disconnected' screen to a connected and running monitor. It will move everything to your primary unless the primary itself is "disconnected".

Solution(s)

1 Manual Mode:

Turn your PC off when done at night, then your monitors off afterwards. In the morning, do the reverse and turn on monitors first and while they are in their 'no source found' error, hope your PC boots up in time before they sleep.

[For your laptop'sake] Your laptop will boot to it's primary screen and not output to the secondary monitors until after booting. So their wake cycle may be too slow between when windows starts to load and sends a zappy zap (technical term) to begin their wake process, and when windows is fully loaded and the "feature" kicks in of moving apps to the online screen.

[For others with PCs looking at this] Problem is many Bios will only output on 2 of say 4 screen thus allowing 2 to go to sleep anyways. If windows boots before those 2 sleep, you are good. if it boots while they are asleep/ "disconnected" your apps will be moved.

2 Third Party Software

While I personally haven't used it, this third party program is cited in several places around Microsoft technet to be able to force/solve this issue. It allows one to make a profile for apps to open on a specific monitor every time.. So their's that..

https://www.actualtools.com/multiplemonitors/features/multi_monitor_window_management/

3 100% Windows scaled 150% forced scale

No Idea how to title this. I do it for my monitor sometimes, but you could do a 150% scaling through NVidia with custom resolution. To Windows, you are keeping it at 100% scaling. The graphics card itself does the 150% scaling by taking an input of 2304x1269 and outputting to the screen a 3840x2160 resolution. I have outlined it below in this screenshot..

Side note

I deal with these issues regularly as the IT guy for an AV integration company. Not all monitors talk to the PC while the screen is off and thus the most hated anti-productivity 'feature' will ruin your day. Above is all I have to offer, I got to the point where I tossed my monitors which appear off to windows while waking to the test bench and now have some dell monitors that always report 'connected' when in sleep or wake mode.

Answer 2

For anybody who's interested, I've actually managed to solve this problem, albeit with a substantial capital investment.

In the end I bought a Razer Core X Chroma with and an NVidia Quadro P2200 GPU, plugged the 4k monitors into the GPU and then connected the Core X to the WD19 dock via TB3 - it all works perfectly, remembers my previous window positions, settings and as an added benefit improves the performance of the laptop day to day considerably. Moreover it'll probably just amount manage some games too.

Honestly I think the Dell WD19 is garbage and was no doubt the source of the problem, so perhaps I should've looked at other TB3 docks. As an alternative I could always bin the WD19 dock and go straight into the Core X (as it's the Chroma edition and has USB/Ethernet on board and the juice to charge the XPS 13), but I decided not to at this time as I still use the audio line out from the WD19.

I can also confirm that this rig works perfectly with my work laptop, a HP Elitebook 830 G6 (8JZ19EC#ABU).

The only complaint I have with the Core X is the PSU fan is quite loud and is constantly in active cooling mode when the unit is in use, but I'm looking into swapping that out for a quieter PSU.