Sleep woes thread 2

[waleery]

Is it possible to add an option to turn off the external monitor when the Macbook is put to sleep? Right now, when I put the computer to sleep, the monitor displays a black image but is not turned off.

Thank you in advance for your answer.

P.S.You created great application

[waydabber]

Hi @waleery - indeed, this is a problem. The root cause is a macOS issue that will keep the display that has a mirrored virtual display on and does not allow it to sleep. This is happening without BetterDummy if you use SideCar or AirPlay mirroring, so this is a generic issue. It was reported to Apple but I bet this is somewhere down in the priority list. Still trying to figure out how to best circumvent this issue (there is some fix for this in the app but it does not seem to work reliably - but on my config most of the time when both sleep related settings are active, the external display can sleep alongside the internal display).

[cprcrack]

Hey, I've just been trying playing with these two options for a couple of hours and while it works sometimes with those two options enabled as you said, I'm also suffering a plethora of different issues a lot of times when one or both of the settings are enabled:

• External monitor freezing with current image.
• External monitor displaying black image.
• External monitor slightly flickering when moving the mouse just after awake until I restart BetterDummy (this one is the worst).
• Internal monitor windows being re-arranged and moved to the external monitor.

In case it's relevant, the external monitor is my primary display. And the auto-arrangement always works well when Disconnecting and Reconnecting manually and when only "Disconnect and reconnect on sleep" is checked, so that part seems to work perfectly.

I have been trying to conclude when and why sometimes these issues happens but I'm sorry, I just cannot reproduce them in a consistent manner. However I'm pretty sure that there is a difference between when you manually go to Menu bar > Apple logo > Sleep, and when the Mac auto sleeps the screens after you do a Menu bar > Apple logo > Lock screen (same thing to pressing the Touch id).

In my case I never manually sleep the Mac, I just Lock the screen with the press of the Touch id button, and it sleeps itself after a few seconds. So my question is, just the same way you are detecting when the sleep and awaking happens to disconnect and reconnect, could you add another option to do the same thing when the screen is locked? A "Disconnect and reconnect on lock" option basically.

I really have the feeling after all my tests that this new setting could really work consistently by itself in preventing all these issues, and the only trade-off is that you need to click on Lock Screen instead of Sleep, but it is very easy to set it up so that after you Lock Screen the system also Sleeps (I believe it's the default in Monterey).

[waydabber]

Hi @cprcrack

Issues 1,2 and 4 are all related to the freezing issue and its workarounds. The core problem is that when a virtual display is in mirror, macOS will not sleep the display but freeze. This is an issue that Apple should fix but they just don't wanna.

The black image is due to the "Use mirrored dummy sleep workaround" which creates a new temporary black virtual display upon sleep. For no logical reasons, this seems to let the displays go to sleep usually (especially when the macbook lid is closed or used on a Mac Mini). Other times it won't let the displays sleep just show a black screen on the external display.

The re-arranging is due to the "Use mirrored dummy sleep workaround" and "Disconnect and reconnect on sleep" as both changes display layouts and macOS handles such things very badly in general.

I detect all sleep events the same way, but since the whole problem is fundamentally illogical (there is a bug somewhere in macOS which is a black-box to us), who know what specific factors influence how the bug manifests itself - maybe the way sleep is induced has some effect.

The thing I would really focus on figuring out is the flickering issue - is that reliably reproducible on your system?

[cprcrack]

The black image is due to the "Use mirrored dummy sleep workaround" which creates a new temporary black virtual display upon sleep.

This may explain something interesting that has also happened to me, sometimes the black screen does have the cursor (and only the cursor) somewhere in there, sometimes even partially like on the edge of the black screen. Maybe if the cursor is drawn for some reason on top of the black screen the hack no longer works as it's now not all black?

The thing I would really focus on figuring out is the flickering issue - is that reliably reproducible on your system?

Nope, unfortunately it just happens sometimes (let's say about 25% of the times I have both options enabled) and I have not found why it does. I have tried for example without the MonitorControl app that I also use but there seems to be no effect. If I don't move the mouse the flickering stops. It's lie a subtle but noticeable +-10% brightness change whenever the cursor position changes by one pixel.