Here's a weird one. 2020 M1 Macbook Pro, running Big Sur 11.6.2.

I've just got a new monitor - Samsung Odyssey G5 34", 21:9 resolution (3440x1440). I have a Hyper Drive Pro Hub (8-in-2) plugged into the macbook, and into that is a USB A cable for my devices (keyboard, mouse dongle, camera and USB soundcard), then a Yubikey plugged into a USB-C port, then the power, and finally an HDMI cable to the monitor.

The monitor is set to 60Hz.

When I first plug the dock in in the morning, the monitor doesn't always work - just shows black. If I change the resolution down to 1920x1080@50Hz it then does work. Just now, I wondered if it was a power issue, so clicked the battery icon in the toolbar which said "holding at 85%, will charge to full..." - so it's using optimized charging.

When I then clicked the 'charge to full now' button, the screen would let me go up to full resolution.

What's going on here? My guess is something to do with bandwidth and power delivery, but I've no clue what.

I have also ordered another dock by a different manufacturer, so I'll see if that is any different.

Update: the new dock (an Anker one) is working fine, so my guess is it's to do with USB/thunderbolt bandwidth and power. Still weird though.

2 Answers 2


Not all hubs are created equal and some cannot cater for the energy needs of all the peripherals AND the laptop. Some hubs are PD 60W only and that might not suffice.

Example: 30W adapter for MB Air can charge the laptop without issues. I can connect a Lenovo M14 USB-C screen to it - charging still works but is considerably slower. Now, the Lenovo screen also does PD, but when the chain is adapter->Screen-Air, the charging is ultraslow to 'negative' depending on the tasks running. A power adapter from an Intel MB Pro (80 something W) has no issue.

Another thing... HDMI - depending on the cable, it might not deliver the required resolution (at all times).


Monterey 12.0-12.1 has serious problems with USB-C power delivery. I've heard that 12.2 fixes them, but I did not install the beta to confirm it


  • Ah, I'm still on Big Sur 11.6.2! I'll update the Q.
    – shearn89
    Commented Dec 30, 2021 at 9:01
  • Here I am always assuming everyone has the latest.
    – muskwasis
    Commented Dec 30, 2021 at 9:14
  • It's a work laptop so its not completely under my control.
    – shearn89
    Commented Dec 30, 2021 at 9:25

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