3 monitor setups. Only 1 monitor fails to work for "Night Mode"  

I have three monitors for my setup.
Asus VG278 (main)
Asus VG248
Asus VG245

I'm dual booting Windows 7 X64 and Windows 10 Pro X64 (Version 1909, OS Build 18363.592).
But the problem only applies to Windows 10.

I turn on the night mode on and night mode doesn't come on for the main monitor.
I found a way to solve this problem temporarily in a rather tedious manner but it's not a viable solution.

What I have to do to make it work is to change the monitor refresh rate and then all of sudden the night mode works.
This is very strange as I've never experienced this with Windows 7 by using Eyesaver app which has a similar effect as Night Mode on Windows 10.

So, I'm looking for a better way to fix this.

I have experienced this once on a system that turned out to be the work of the GPU "Tray Icon" where I had to remove it and even turn off its service from services and startup entry .

But to note the GPU driver was released pre-Night Mode and it turns out it refresh display settings every now and then ignoring applying Night Mode filter again because apparently it wasn't available back then when it was developed .

This might not be exactly what you have but you may give it a go as an option .