EDID is just temporary information that the monitor sends to the computer that describes the monitor's capabilities so that the computer knows what the monitor can handle. EDID is often wrong or corrupt, especially on OSX, but it happens in Windows too.
A monitor's INF file is a little bit more permanent, acting sort of like a Windows driver for the monitor.
I'm not sure what Custom Resolution Utility does, but I speculate that it is either temporarily overriding the EDID or it is doing what a monitor INF file does.
So a firmware isn't really involved in any of these. But it is possible if this is a new monitor model that there could be problems with the monitor's early firmware and perhaps there will be a fix. I've never heard of that for a monitor though.
Anyway, because I did a clean installation that doesn’t work. So, I restore the backup from WinClone. And suddenly, the display port able to display something with the assist of HDMI connection (use the monitor as dual monitor setup, display 2 signals side by side).
And after re-select 3840x1080 on the display port side, I can now disconnect the HDMI cable and enjoy the 10bit HDR 144Hz ultra wide monitor. I really don’t know what’s wrong before. Most likely you are entirely correct that Windows get some wrong EDID info. But anyway, it works now. So I better not to touch any setting, or perform any update
Also, it’s time to think about if I want a RX580, or Vega56, or GTX 1080