Virtual display text scaling issue in Windows

[stderr-to-devnull]

I set my Moonlight client resolution to 1080 and in Apollo I set to use the virtual display resolution set in the client.
When connecting from the client by clicking on Desktop the text is VERY small (the resolution is correct) and the scaling drop-down options in the display properties are greyed out. I set custom scaling to 150% to ZERO effect (I reconnected afterwards).

Then, I tried to check the scaling from the host but the virtual display is not present when no streaming connection is active.
I did however notice that the scaling on my main (physical) monitor was also greyed out. I clicked on advanced scaling and my whole session was abruptly interrupted, all my apps closed and I was logged out.

1. Why is there a huge discrepancy between text scaling and virtual display resolution?
2. Why is the scaling greyed out on the virtual display?
3. Why is custom scaling having NO effect?
4. Why did the custom scaling affect my physical monitor settings (just the options, the scaling remained OK)?

The most egregious aspect of all of this is the fact that just attempting to revert/reset the scaling options on my main monitor instantly logged me off, closing all my programs. This might be a Windows quirk or not, I have no idea but I also had no idea that this would happen, there was no warning, no confirmation. This whole situation was triggered by the faulty behavior of Apollo.

Lastly, the settings and setup are very poorly documented (almost non-existent).

[ClassicOldSong]

Some monitors can have weird configurations that made scaling not adjustable. For virtual display related things, you need to adjust them during the stream and usually they'll be saved by Windows automatically. If not, your installation of Windows might have some issues.

Advanced scaling usually isn't recommended to use unless you have very specific needs.

[stderr-to-devnull]

As I mentioned, the scaling on my physical monitor works without issues, all options are available and I did them already 3 years ago.
As I mentioned, I tried adjusting virtual display settings during stream but scaling options are greyed out and only custom scaling is available which I tried to adjust to no effect.
As I mentioned, the attempted custom scaling on my virtual display affected the scaling options on my physical monitor (without scaling being modified) for whatever reason and attempting to recover the normal scaling options closed all my programs and logged me out.

I repeat, for maximum clarity:

• the virtual display text scaling is problematic -> text is too small for given 1080p resolution
• the virtual display scaling settings (only for this display) are greyed out, only advanced (custom) scaling is possible as a setting
• attempting to set a custom scaling percentage on my virtual monitor during streaming (tried 125% and 150%) does not change the text scaling
• attempting to set a custom scaling percentage on my virtual monitor during streaming affected the scaling settings availability on my physical monitor, leading to the logout I already mentioned when attempting to recover them

your installation of Windows might have some issues.

Elaborate this conclusion, based on what aspects did you reach it?

You never clearly stated that:

• scaling on virtual monitor during streaming on Windows 10 works properly out of the box (no scaling needed or no scaling issues)
• adjusting scaling on virtual monitor during streaming does something
• all normal scaling options are available on virtual monitor during streaming

Did you ever test this, can you confirm? Is this aspect documented somewhere?

[ClassicOldSong]

I have tested and lots of other users can adjust dpi without issues. That's why I suggest you to check your windows installation.

Set custom scaling is global as described by Windows and requires logout, that's why you're seeing all the problems. They're all notified to you by Windows before you confirm the settings.

As this is a free open source software, I have no responsibility to solve your specific issue since most other users including myself have no problem with it.

You can try clearing your monitor cache as described in the FAQ in Wiki and see if it solves your problem.