I have a Chineese brand whiteboard that has a maximim resolution of 4K @ 30Hz and that works fine in Windows 10, but it fails in Linux O.S.
When you start the Linux OS in the OPS the monitor goes off and the "NO signal" message appears on the screen. The very same monitor with the HDMI cable works fine, but as a displayport (OPS connection) it just goes off.
Also with the Glamor driver it seems to fail allways, but with the Intel driver in SNA mode, it works fine for other (lower) resolutions but it does not work for 4K resolution.
I've attached SSU reports (Windows and Ubuntu 18.04) and also "xrandr" command verbose output and "dmesg" command output.
If you need something else let me know.