I have a MacBook M3 running macOS Sequoia 15.1, with two monitors. When I finish using it, I walk away (no logout, no sleep, just walk away). When I come back and unlock the screens, all application windows have (usually and maybe always) moved to the primary monitor. (Desktop icons on the secondary monitor stay where they were.) Is there some way I can get the windows that I put on the secondary screen to stay on the secondary screen? Thanks.
FWIW, the MBA has one port in use; it is connected to a CalDigit TS4 hub’s input Thunderbolt port. The primary monitor (Apple Studio Display in portrait mode) is connected to a Thunderbolt port on the hub; the secondary monitor (Acer H277HU) is connected to the hub using a DP cable.
Edit: I just noticed the following in the TS4 manual.
The DisplayPort on the TS4 is only compatible with active DisplayPort adapters. If you attempt to use a passive adapter, your display will not function correctly. If you are not sure which type you have, please check with your adapter manufacturer to ensure that it is an active adapter.
Aside from losing the application windows, the secondary display seems to work just fine. However, I have no idea what an active adapter is or whether I have one. The DP cable is the one that came with the Acer display.
Perhaps the 2nd monitor doesn’t wake as fast as the primary monitor. So, on wakeup, the system doesn’t see it and sends all screen output to the primary monitor.
I have the same issue, and did under 13 and 14 as well, for as long as I’ve been using this setup.
In my case, the secondary display – and the one windows get kicked off of – is my laptop’s internal display. If it’s just a matter of sleep-wake timing, you’d think the laptop would wake its internal monitor before (or at least at the same time as) the one plugged into the Thunderbolt dock.
EDIT: Watching carefully, I do see the external display light up first.
Thanks. The Acer display does illuminate a second or two after the Studio Display. For the last four times I woke the computer, I first turned off the Acer display, turned it back on (and waited for it to cycle through its inputs), then pressed a keyboard key to wake the Mac. All four times, the windows that had been on the secondary monitor were still there, so it does seem like the Acer display lags.
The Acer H277HU has a USB-C input and my MBA M1 (Big Sur) can use that monitor through a USB cable with no problem. I thought perhaps using the second Thunderbolt port of the MBA M3 to connect the Acer display by USB would wake the display more quickly. Instead, the display never wakes; apparently the MBA M3 cannot communicate with the Acer display over USB. Why would that be? (On a perhaps related note, I connected the Acer display to the CalDigit TS4 using a USB cable in addition to the DP cable. A wired Apple mouse connected to one of the Acer’s downstream USB-A ports works fine. A wired Apple keyboard similarly connected to the Acer does not. Why would that be?)