DELL D6000 + Macbook Air M4 - only 2 monitors

[ericslaw]

I have this same issue.

MacBook Pro M1pro + D6000 connected 3 monitors - all 3 monitors is working (two displayport and one HDMI in displayport alt mode / passthru.
MacBook Air M4 + D6000 connected 3 monitors = only displayport monitors working

The displayport passthru itself does not use displaylink technology that I know of.
I think the key difference here is the M4 uses displayport 1.4 while the M1 uses displayport 1.2
I dont know what version is used by the D6000 but I suspect it has to do with the M4 handling two displayport streams whereas the M1 only has one.

Some other discussions found:
https://discussions.apple.com/thread...35?sortBy=rank
https://forums.macrumors.com/threads...rking.2453395/

also related - how the D6000 handles only two displays - it will always use displaylink instead of DP Alt Mode: https://www.displaylink.org/forum/sh...60&postcount=7

[Szymon]

Hi ericslaw,

Please make sure to update macOS to 15.7.x or newer.

PS. D6000 DisplayPort ports are driven by DisplayLink. The only Alt-Mode port is HDMI.

Regards,
Szymon