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

My Macbook Pro 13 (2020 4*Thunderbolt 16G ram) also has this problem.

I contact Apple and tried all the solutions even go the service center. Still same !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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 was having this problem and greatly improved it by getting a bidirectional thunderbolt to viewport cable. Amazon Basics sells one. It has happened a couple of times since I replaced a unidirectional cable, but turning the screen off and on works now without disconnecting it. I would also look at separating the display cable from power cables to avoid interference. I’m not sure this matches your setup, but hopefully it helps.

Re: my one and only previous post about a month ago: my new Mac mini m1 works perfectly with a display monitor if attached via usbC to vga adapter. So that is the perfect work around for me. (Ie. I avoid using the M1 HDMI port, since it worked only sporadically if at all).

I am using one of the M1’s usb-c (thunderbolt) ports to connect to a viewport monitor. My monitor does not support its highest resolution with hdmi input. I have not tried using an html to viewport converter; many of those seem to be unidirectional for an hdmi monitor.

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.

I connected my Mac mini M1 with an MSI Mag321Curv. I got the same problem using USBC to USBC where the Monitor does not wake up from sleep. I switched to HDMI to HDMI and the problem became less in frequency. Additionally, there seems to be no IOS driver for MSI and the MAC shows the Monitor as "No Name". Anyone has this problem? Thanks.

Had this problem with macbook air m1. It seems to me that it worked when I moved the keyboard and mouse to a single direct USB port on the mac (don't use the USB hub on the Dell monitor, nor the USB ports on the USB C / HDMI dongle).

I don't believe it's the monitor because connecting to a remote Mac mini through the Finder using "Share Screen..." will also mostly not wake up after the remote Mac mini sleeps. This is probably why the sleep bug is so difficult to trace.

By the way, you can wake up the remote Mac mini by resizing the share window.

Sorry but this cannot be the answer on the long term. I NEED and WANT to have separate spaces for each display, otherwise I don't need two separate displays. Reducing the extent of functionality cannot be a solution! The problem needs to be solved on Mac OSX. And this case simply hasn't been taken into account by the developers. So please Apple get a solution to this, because this seems to be a serious problem with more than 600 people having the same issue.

I have discovered something that seems to make a difference in my particular setup.

Into the left-hand thunderbolt/USBC port I've got a monitor connected via an HDMI>USBC adaptor.

Into the right-hand thunderbolt/USBC port I have an external SDD drive connected.

In this arrangement, I don't seem to have problems with that monitor failing to wake up.

However, with the monitor plugged in via the right-hand port, I do. This is how I had it previously - and was continually having problems. When I swapped it around (unintentionally) when moving my computer, the problem went away.

I tried swapping it back and the problem returned. I've now swapped it back again and things seem to be OK.

Won't be surprised if it starts happening again for some unknown reason though!

A year later and it's still a problem. So much for them fixing it. Having to forego separate screen spaces in order to work around a bug in their buggy OS isn't a solution. 

The problem is the same. HDMI (main monitor) just shuts itself down after sleep and never wakes up, even un/plugging hdmi cable doesn’t wake up the display (yes, it's on). Tried lots of things, restarting numerous times. Nothing worked. BigSur doesn't even recognise that there is a monitor attached. I have to restart the computer for it to work again.

However,  "mac_i" above may have found the root of the problem as I too have a video adapter fitted into the right hand thunderbolt port and it's only been happening recently, and recently I moved the adapter from left to right usbc port.

Plugging usbc-video into the left usbc seems to have fixed it. Been a day or so and hdmi now wakes up when computer wakes up, every time (about 20 times so far). The adapter also wakes up as well (it always did).

So problems with the right hand (closest to hdmi out) seems to be the culprit.

Failure to wake up after sleeping also happens virtually using Apple's "Share Screen..." facility built into the Finder. The fix is to resize the shared window, and it wakes up. Trying to find a hardware cause is probably why Apple has been hard pressed to track this problem down.

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".