I /think/ this is related to the EDID support or configuration.
What I do know is that you need specific EDID support when using a DisplayPort KVM because that switches the computer away on a regular basis. If you have multiple screens and a single screen KVM (fairly common) it will do the re-arrangement that you've experienced. With EDID support it keeps both output alive resulting in no re-arrangement.
EDIT: It seems the correct term may be "EDID emulation".
> If you have multiple screens and a single screen KVM (fairly common) it will do the re-arrangement that you've experienced. With EDID support it keeps both output alive resulting in no re-arrangement.
Can you tell me some KVM switches that have a working implementation of that feature? I'm looking for one.
I'm still using a DVI KVM, because when I tried to upgrade to Displayport (years ago), I ran into the problem you describe and gave up.
It has been OK for my needs, but I think you are best getting the KVM and returning if it doesn't meet your needs. I'd probably be more concerned if this was for my photography or gaming machine. For a work setup it has been fine for me.
What I do know is that you need specific EDID support when using a DisplayPort KVM because that switches the computer away on a regular basis. If you have multiple screens and a single screen KVM (fairly common) it will do the re-arrangement that you've experienced. With EDID support it keeps both output alive resulting in no re-arrangement.
EDIT: It seems the correct term may be "EDID emulation".