I have been frustrated to no end on this issue and can’t seem to find anything on the internets that can help.
I have the MBPro M1 (2021). Main display is an LG 38WK95C-W 38-Inch Class 21:9 Curved UltraWide and my secondary monitor is the old school Apple Cinema Display. I have both displays plugged into a CalDigit TS3 Plus Thunderbolt 3 Dock. When I utilize these displays, the MBPro is in clamshell mode in an upright stand. I’m running Monterey (12.5.1).
When the MBPro goes to sleep and I try to wake it by pressing a button the Apple Bluetooth keyboard, or pressing/touching the Apple MagicPad, the MBPro wakes up but it can’t wake up the displays. Sometimes, the displays will wake up, but 95% of the time I need to open up the MBPro, unplug the Thunderbolt cable, plug it back in, then close the MBPro lid. Super frustrating considering that my old MBPro had no problems waking up both displays with the exact same setup. I also have a StreamDeck and it always wakes up.
Interestingly, if I restart the computer in clamshell mode using the external keyboard, the MBPro can restart and power on both displays.
Is there any fix to this so the MBPro can always wake up the displays without having to open up the MBPro?
I have two displays plugged into my M1 laptop as well (which is in clamshell mode). They usually wake up okay however they sometimes wake up with different resolutions and orientation (switch left and right). One of my monitors (Pro XDR) is plugged directly into the laptop, the other via an OWC T4 dock.
I haven’t done anything special on my config that I’m aware of though.
I have been talking to the dev behind switchresx and it does appear that the monitors are a little loose in their configurations when starting up and with the Mac driver as well.
In your case, I wonder if the dock is going to sleep and isn’t waking up. It sounds like unplugging the dock from the computer and back in again (without opening the laptop) doesn’t wake the dock up? What about remove / plug in the power to the dock?
I thought that the M1 (non-Pro, non-Max) MBP doesn’t support multiple external displays?
For what it’s worth, I’ve always found multiple external displays to be a bit flakey. Sometimes they work well and sometimes one (or the other) dispaly just won’t wake up.
Related: I have a 2019 MBP connected to a 2010 Apple Cinema Display with an HDMI switch. When I flip the switch to the MBP’s position, the MBP connects to the display—I can tell because the windows disappear from the desktop—but the display does not light up. I have to unplug and reconnect the display from the MBP’s USB-C port.
I do not have this problem with the Lenovo laptop that connects to the other port on the HDMI switch.