Unreliable switching to USB-C source


I use my Spectrum connected to two computers: a Monterey MacBook Pro via USB-C, and a Windows 10 PC via DisplayPort.

To switch between the two computers, I wake up the new computer, then ask the current one to put its display to sleep. (⌃⌘Q on macOS, which locks the session and put the Mac to sleep; and the power button on the PC tower, which turns off its video output)

The switch from the USB-C MacBook to the DisplayPort PC works every single time, albeit a bit slowly.
However! The switch from the PC to the Mac is fairly unreliable; something like 1 in 5 times, the Spectrum stays black for 10-20 seconds, before showing (IIRC) “No Signal”. At that point, disconnecting+reconnecting the USB-C cable fixes the issue, and the Spectrum shows video from the Mac.

Of note, this is with the Mac open—not in clamshell. Clamshell makes things far less reliable still, but that might be a bug with macOS.
The screen is a 144Hz 4K Spectrum running firmware 105.

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Hi @Cykelero,

I dont own a Mac, so I can’t replicate your setup. But…
We have 106 coming soon which will improve USB hub functionality.

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  • 106 did not fix the issue.
  • I had to downgrade after installing 107, as it would cause my Mac to kernel panic as soon as the Spectrum display was connected.
  • After trying 108 for a few days, I can confirm it doesn’t fix the issue either.

I’d like to reiterate how severe the issue is: whenever I wake my computer up, I have to manually disconnect and reconnect the display cable, repeatedly, over the course of a minute or so, to have the display start connect to the Mac.
Though for some reason, the situation has slightly improved lately—I often only need a single disconnect cycle—it’s exhausting and bewildering that the basic function of the display (showing an image) could be this flaky, more than a year after the thing’s release.

Have you been able to reproduce the issue? Do you have a plan for a unit recall, or maybe refunds?

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