mac mini m1 resolution resets after long sleep

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mac mini m1 resolution resets after long sleep

When I sleep my M1 mac mini 16b overnight, it wakes to the MINIMUM resolution. A screen grab here is captured at 1280x720.

When I then reboot the machine, the resolution matches my monitor. The screen grab below has the resolution 3840x2160.

If I sleep the machine during the day, and leave it for a couple of hours, the resolution also does not reset. It only happens if I sleep it overnight.

My mac also suffers from the dreaded https://discussions.apple.com/thread/252106534 flicker bug that seems to plague the 16gb M1 minis.

Mac mini, macOS 11.6

Posted on Oct 7, 2021 3:02 PM

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Answer 1

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Tim St.Clair Author

Level 1

80 points

Oct 8, 2021 7:33 PM in response to den.thed

I have tried both HDMI and DisplayPort. I have bought short premium gold plated HDMI at vast expense only do discover that it does not in fact solve the problem. I have bought usbc to displayport cables, also at their highest quality shortest I can find only to discover these also behave exactly the same as cheap cables in that it does nothing to address or fix the problem. Many of the people replying on the other thread I linked also describe the same deals with quite a variety of displays.

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Answer 2

Tim St.Clair Author

Level 1

80 points

Oct 13, 2021 6:21 PM in response to hcsitas

The display will now wake to its native resolution overnight.

But if the display sleeps during the day for a short period, it will wake to its lowest supported resolution about 1 in every 3 wakes during the day.

This is effectively backwards to how I first reported the issue.

Once the mac is displaying in its lowest resolution, the display preference panel is no longer able to display the monitors list of supported resolutions, just showing the set of fallback resolutions.

I have to restart my mac in order to get the resolution back up to 4k.

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Answer 3

hcsitas

Level 6

13,124 points

Oct 7, 2021 9:33 PM in response to Tim St.Clair

Disable sleep, it’s not needed on later Macs. Check “Prevent…” in Energy Preferences and uncheck everything else except auto start on power fail. As for flicker, there’s no plague except the old one of lazy monitor manufacturers who won’t test their glass with Macs. Maybe disabling sleep will fix it, if not post details please.

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Answer 4

den.thed

Level 10

83,194 points

Oct 8, 2021 7:24 AM in response to Tim St.Clair

Are using an HDMI cable or USB-C to DisplayPort cable to that ASUS VP28U?

If you must use HDMI, try a short Premium Certified HDMI cable.

If not, then you should test that setup using a USB-C to DisplayPort cable.

Plus I also concur with hcsitas, to check "Prevent computer from sleeping auto......." and only allow the Display to Sleep when your not using it.

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Answer 5

Tim St.Clair Author

Level 1

80 points

Oct 9, 2021 11:21 PM in response to hcsitas

Yes (left it a couple of days to validate), and since the machine isn't changing state the resolution is holding. The flicker/line problem still exists, but that is a separate issue. Restarting still holds the resolution, at least so far.

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Answer 6

hcsitas

Level 6

13,124 points

Oct 13, 2021 9:02 PM in response to Tim St.Clair

Looks like it’s fixed 80%. Note that the display doesn’t “Sleep” but is turned off by command. If it doesn’t switch on to proper resolution (1/3 after short periods), it would indicate an issue on the Asus monitor. What about flickers? Have they improved/gone? The point is, that there’s nothing else on the mini side that can be done; we (you) now need to focus on the Asus settings to get from 80 to 100%.

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