Hmm, this’ll get tricky to investigate. It sounds like newer versions of particular pieces of software have broken this.
If there’s a bug report, or one you could re-produce, this would greatly help fix the aging X server for both distros.
However, let’s see what versions are in use for:
- CentOS 7 with MATE (when working)
- CentOS 7 with MATE (updated, but broken)
- Optionally, Ubuntu MATE.
Of the following packages:
lightdm-
Xorg(not at PC right now to get its package name) - NVIDIA version.
- Kernel version (
uname -a) - Anything else that might be related to X.
Synaptic will be useful in Ubuntu for viewing package versions. I’m afraid I don’t know the equivilant for CentOS.
You may be able to lock and use older versions of the affected packages, while keeping the rest of the system up to date. Kind of like super gluing old parts until (and if) it’s fixed.
You could try Ubuntu MATE 14.04 to see if we can filter down when abouts this issue kicked in. With UM 14.04 being an “unofficial” release at the time, it’s not really supported now that 15.04 onwards became “official” and uses the official infrastructure from Canonical.