Mac Studio + LG UltraGear QHD/2k = Workspaces/apps re-ordered on different displays; vertical screen shifting; blurry image @ 120 Hz.

Also seems to be in relation to: M1 Mini issue with LG 27" 5K Monitor - Apple Community

My Setup:

• Mac Studio M1 Max.
• 3 x LG UltraGear QHD/2k Monitors (LG 27GL850-B).
• IOGEAR GCS1964 KVMP, with DynaSync/EDID support.

macOS:

KVMP Connections:

• 3 x HDMI from Console to each Display (supplied by IOGEAR for KVMP).
• 3 x USB-C from Mac Studio to DisplayPort on Console (2k/144 Hz).

All issues are caused when waking Mac Studio up from sleep or switching KVM ports. None of these are issues present on either of my PCs, Ubuntu (on-board video) and Windows 10 machines (RTX 3080).

This was also NOT an issue with my late-2018 Intel Mac mini with external GPU/Radeon RX 580.

Issue 1:

Workspaces (virtual desktops?), desktop icons, or Applications may be moved from one screen to another upon wake up. It's as if some Interdimensional hobgoblin comes to my office at night and physically reconnects the cables to a different display, where contents of Display 1 will end up on Display 3, or contents on Display 3 will end up on Display 2.

Mac OS also does not remember the settings for the displays, it always auto selects Scaled instead of Default for Display for one or more of the displays. All of my displays are the exact same make and model, however two of them sometimes show as "4k" (and I can select it and it will work, but appears to be scaled) and one of them is "2k" despite ALL of them only being 2k. I don't know if this is part of the problem, but each time I reboot or wake up, the Display settings for these may change.

And this happens randomly after waking my Mac Studio up. Sometimes it's fine, but a few wake ups later, it's a mess again.

Display 1.

Display 2.

Display 3.

(Note: Two are at 100 Hz because one of the screens will blink in and out if all are 144 Hz.)

I also tested keeping the Mac Studio on all night while changing the KVMP port (to keep monitors off) and still the issue persists, in fact one of the monitors never turned on when keeping the Mac Studio on all night, I had to unplug and replug just to get it back on.

Issue 2:

When waking up the Mac Studio, there is an issue with one of the monitors that's very annoying. Half the screen will be shifted a few pixels, as if there's tear in the middle of the screen. I have to switch ports back and forth on the KVMP to "fix" it, but it'll happen again on the next wake up.

This shows the login screen with the pixels shifted on half the screen.

This shows after I log into the Mac Studio, the shift in the center, but also to the left, it's showing another space as if I was swiping my Magic Mouse to switch spaces.

Again, none of these issues happen on my PCs or my Mac mini w/eGPU.

Issue 3:

All three of my displays support 100 Hz, 120 Hz, 144 Hz. However I am unable to drive all three at 144 Hz on this Mac Studio — if I attempt to do so, one of the monitors will continuously blink off and on until I change the refresh rate to 100 Hz.

I would like to set all three to 120 Hz however there is a major issue with this: While the screens will display at 120 Hz, all of the images will be blurry, as if some blur filter was applied to all the screens. I don't understand why it does this.

On my PCs I can set them all to 120 Hz and everything is crisp and clear.

On my Mac mini w/eGPU, I can set them all to 120 Hz and everything is crisp and clear.

Only on Mac Studio will everything become blurry at 120 Hz.

I wonder if it's because it's sending a full 120 Hz signal, where as my PCs are sending exactly 119.988 Hz?

At 100 Hz or 144 Hz:

At 100 Hz (simulated since photos don't show it):

I took these steps to try and solve some issues:

I replaced ALL cables specifically for the specs of my monitors. I also used the cables that came with my IOGEAR KVMP so there is no question on the requirement, but I also tried third party cables and the results are the same.

I contacted IOGEAR support for the KVMP, they believe that the Mac Studio is the issue here: Their KVMP requires a direct connection (no adapters, no docks), and they consider the USB-C to DisplayPort cables to be an adapter, and because of that they can't help with the issue. (Obviously I have no choice but to use these cables with the Mac Studio).

It may explain why my PCs never have this issues since they are going from DP to DP, or my Mac mini with eGPU which is also going from DP to DP.

Can any of this be fixed?

I know some of these issues have been reported for YEARS (and some have been an issue for over a decade). I've read hours worth of threads from various forums, from various web sites, and it seems nobody has ever found a solution to any of these issues, or at least not one that I can find that has been a confirmed solution.

There has to be a solution out there somewhere.

I Want To Believe.