M1 Mac Mini, Displays wont turn on after wake from sleep

I have the same issue. Im using a single external monitor, disabling sleep on the mac does not help. Oddly I did not have this issue until a month after purchase and now have it constantly. I think the monitors own sleep function which kicks in after four hours may be the 'trigger' for the issue. That said this is truly an Apple problem in that it can't communicate with a monitor after the monitor sleeps or will no longer send signal to a monitor after the monitor has slept.

I don’t want to hazard a guess—there still could be a problem with the hdmi cable that you are using on the one monitor. Is the second one also an hdmi? Or a viewport? Whatever cable you were using from the M1 usb c is suspect to me.

but, hey, you can return the converter if it doesn’t work. I do think that Apple has a couple of problems with M1 with monitors and Bluetooth and it is probably worth calling them just to join the chorus.

Not sure if this is related, but my Dell U2913WM display, connected by USB-C to Display Port fails to turn back on if I turn the monitor off using the touch button on the front.

No response from the monitor at all until I unplug the USB-C at the monitor end then turn the monitor on (button responds now) and then hot plug the USB connector again.

Putting displays to sleep (hot corner) works fine. Its just annoying if I accidentally catch the touch sensitive button or if the spouse helpfully turns the monitor off because I'm not there, then I cannot switch it back on whilst connected.

It's been about 6 months since I bought this Mini and there have been multiple OS updates - I think it came with 11.2 installed. Apple has had plenty of time to provide a software update to fix this issue and since they haven't seems more likely that it is a hardware issue. Don't know about the share screen issue. Just a guess but I've been using Macs for a long time (IIsi was my first) and have seen plenty of"issues".

I have a Mac Mini 2018 model and 4 (FOUR) different Dell monitors that I've tried one at a time or in multiples. This happens intermittently with all of the Dell monitors in all situations. Sleep setting are irrelevant. This needs to be fixed! I'm reading comments from user with the same issue from a few years ago! Unacceptable. Apple has something like $250 BILLION dollars in CASH in the bank. They can't figure it out?

Apple is going crazy trying to fix this problem, but until they realize it happens with NO monitor, using "Share Screen" to another Mac and the WINDOW locks up exactly like a physical monitor, then they will never figure it out.

I have a very similar problem. I have a new generation M1 Mac Mini connected to a new LG HDR QHD Monitor via USB-C cable, and the mac mini does not switch on this monitor at least half the time, and perhaps even most of the time. I try everything, and nothing works until I physically unplug the USB-C cable and plug it back in. It will only then come on to my home screen.

I've just updated to 12.1 too.

It's not enormously better though it is more successful at recognising the screen on the USB-C port and bringing it up.

However, there's often a delay and it always relocates all my open windows to the other screen. I work with a lot of windows open so this is a total productivity killer.

I wonder if the relocation of windows happens when I switch away from this Mac to another machine on the KVM switch rather than when when I switch back and the screens come on again (i.e. there's a timing difference when the screens go off that causes the OS to think one screen is gone and the other still connected). Whatever the cause, when I return to this Mac the windows are all moved. It sucks!

My Mac mini has had several problems

1) I turn on WiFi and the monitor (2 of 2) connected to a USB-C hub via HDMI goes blank. Now have to use ethernet.

2) Waking from sleep is hit and miss! Sometimes it works and sometimes it does not. I have to unplug/replug the monitors.

3) My monitors get flipped (L<->R) sometimes when they do come out of sleep.

4) Cannot use cordless mouse/keyboard the connection is intermittent. This same keyboard mouse worked on my old MacMini (2012) for years. Tried 3-4 different combinations and all exhibited the same behavior. Now use wired mouse/keyboard (Same wireless that does not work on Mac mini works fine on work laptop (Windows).

5) Sometimes the mouse (wireless/wired) is not responsive to dialog boxes or System Preferences. Can click on close button at top of window but not any selection within box. Only way to fix is reboot!

IMO this Mac mini is a prototype at best and is the first Apple product that is really a POS. I've been using Macs since the original G3 iMacs. iPhones since 4S, Apple TV (4 different) since original PPC version. Apple really laid a turd with this!. (I love the M1, just not the supporting HW).

Are you sure it’s not your keyboard? Try wired.

Yes. Many of us are having big issues with the new Mac mini and multiple monitors. They say that Apple is looking into this. https://discussions.apple.com/thread/252072263

Ah, the dongled monitor issue, an old, familiar problem. No fix for that I’m afraid other than to get a better dongle or better, a monitor that connects without one. Good luck!

1 monitor, HDMI connection using Apple's USB-C Digital AV Multiport Adapter. Same adapter and monitor worked fine on my previous Intel MacBook Pro running Big Sur.

Ah, dongle. Chuck it, don’t need it for the M1 mini.

There’s nuthin’ to fix...disable sleep and move on. There’s plenty of real problems to be found and fixed, don’t worry. This one though, is fake therefore best forgotten. Enjoy...