External Display Settings reset using USB-C KVM switch

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Level 1

6 points

External Display Settings reset using USB-C KVM switch

Hi Folks,

I have been a Mac user for around 20 years and love Macs for the simplicity of connecting to UNIX and Linux systems as well as the all round awesomeness of the platform.

Recently, I updated my 2021 MacBookPro 16 to Ventura 13.1 and then more recently to 13.2. Now, when using my USB-C 8K KVM switch, the display will randomly reset the display settings to whatever it likes. Prior to updating using this KVM switch, it would remember the settings and re-populate the windows in the external monitor as I had them before.

Now, when I switch from the Mac to the Windoze laptop I have from a client using the same 8K USB-C KVM as before, the display settings are all over the place. Sometimes it will mirror the main display, other times the main display mirrors the external (49" ultrawide Samsung). Sometimes the arrangement defaults to the initial setting. usually the resolution on the external is set to a lower value.

Upon resetting the display settings after it is all messed up, the display resolution list is displayed and the maximum refresh rate is set to 100Hz, other times I get the generic 5 idiot boxes (Large Test to More Space) and refresh rate is 144Hz.

It is like the Mac no longer remembers the settings like it used to in previous OSX versions and has to re-sample the display, usually getting the values wrong. It is First World Problems, but is frustrating when I need to quickly switch from one machine to the other for work.

Any useful suggestions gladly accepted.

Regards

Stewart

MacBook Pro 16″, 13.2

Posted on Feb 5, 2023 11:37 PM

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Answer 1

35Dodge Author

Level 1

6 points

Feb 10, 2023 08:13 PM in response to JJRASC

Hi JJRASC

I am not new to Mac, having used/owned Macs for some 20 years and have also been involved with the IT industry for longer than I care to recall. I have tried a bunch of things. This only began upon upgrading to Ventura. The exact same cabling worked perfectly prior to this. Directly connecting to the monitor will defeat the purpose of the testing as it is the act of switching between the Windoze computer and the Mac that triggers the resizing / reconfiguration mentioned in my original question.

It seems to me that Ventura is not maintaining the settings and is re-detecting (unreliable) the monitor configuration. Prior to the Ventura upgrade (just to confirm, this was on the very same MacBookPro) the monitor settings were kept and everything reverted to where it was either when switching or when reconnecting the laptop. The cabling configuration uses an USB-C connection. I have just ordered a DisplayPort KVM so I will see what happens with that.

the only variable here was the upgrade to Ventura.

thabks for responding.

Regards

Stewart

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Answer 2

Miche11e_P

Community Specialist

Feb 11, 2023 02:11 PM in response to 35Dodge

We appreciate you sharing these details, Stewart,

If you haven't already, you can also check out additional troubleshooting for your external display such as updating the firmware here: If your external display is dark or low resolution - Apple Support

"Update software

Software can affect display detection, the quality of the image on your display, and the resolutions and refresh rates available to your display.

Install the latest macOS updates, which also deliver firmware updates for displays made by Apple.
If your display is not made by Apple, make sure that it's using the latest firmware from the manufacturer. Check your display's documentation or the manufacturer's website for details."

If you're still experiencing the same behavior, we'd suggest that you reach out and report it to Apple directly here: Contact Apple Support

Take care!

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Answer 3

JJRASC

Community Specialist

Feb 7, 2023 02:47 PM in response to 35Dodge

Hello 35Dodge,

Welcome to the Apple Support Communities.

As a way to isolate out any connections that may be causing the display settings to reset for your Mac, you can try connecting your Mac directly to your external display following these instructions: Connect a display to your Mac.

This next article can help you optimize your display settings to get the best picture from your Mac: If your Mac display doesn’t look right.

If you continue to notice an issue, please try connecting your display with a second Administrator user account on your Mac. Click here to learn how to create a new user: Add a user or group on Mac.

All the best!

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External Display Settings reset using USB-C KVM switch

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