laptop:ASUS ZenBook 14 UX425EA, CPU: intel i7 1165G7, to connect a synaptics VMM5200 MST hub (It's a DP1.4 to dual HDMI2.0b MST hub IC)
driver V184.108.40.20639 can works normally at dual 4K@60Hz.
driver V220.127.116.1153 one of the monitor can only output 4K@50Hz and unstable.
driver V.V18.104.22.16890 is not normal.
I found the unstable driver cannot deal DSC correctly.
Thank you for posting on the Intel® communities.
We found another thread describing the same issue and the same hardware/software environment as this one. To avoid duplication of effort, we will close this thread.
We will continue working on this one: https://community.intel.com/t5/Graphics/intel-IRIS-Xe-with-MST-problem/m-p/1225738#M91273
Thank you for your understanding.
Intel Customer Support Technician