2x2 matrix not working

[gertjaap]

Hi there,

I'm trying to make a 2x2 matrix out of my 49" 4K monitor, turning it into four 1080p virtual displays.

I can make a single horizontal and vertical split. It works as I expect it to, showing as two distinct 3840x1080 or 1920x2160 monitors.

As soon as I split one of the remainders in two again, the part that I split becomes unusable. The two virtual monitors seem to be disabled if i open the display settings, but once i enable them the Xserver crashes.

Not sure what kind of logging i can present to figure out what's going on here.

I tried xrandr 1.5 --setmonitor but it's not working (using Ubuntu 20.04 - also didn't work on 18.04)

[mantleCurve]

Having the same issue. single vertical split or single horizontal split works perfectly. but when 2*2 is applied, a blank screen appears. I can see the mouse pointer.

multiple horizontal as well as multiple vertical splits also works.

[huanzhang12]

Having the same issue on Ubuntu 20.10. Single vertical/horizontal split works but 2*2 does not.

[swapsCAPS]

Had similar issue with laptop screen open. Closing it, i.e. having only one monitor, does work here.