I think for league not to change the set resolution in config, you need to add this parameter
[General]
Width=2560
Height=1440
UserSetResolution=1

Anyway, i see you also have a g-sync monitor, so if you are planning to use g-sync in games, you will need to disable those other screens for gaming time... the problem is that for g-sync to work it has to cover the whole screen, but multiple screens will make it virtually a lot bigger than one screen. Better explained in reddit.

So maybe it would make sense, to write a script that will turn other screens off and back on, then make it a macro with if you have gaming keyboard then it might have buttons for that or if not then just assign as keybind.

I already tried to set a new xorg.xonf in the past that doesn't change anything.

and for the unknown monitor, the cables are good changing cable doesn't do anything, and swithing monitors give the same result. It could be something with the Asus VS 238 line of monitor but yes it is very unlikely, but could happen its not because ts works on windows that "working" is a normal behavior. I had some case wioth some products where they work under windows but not under linux and it was because windows was more lenient on the hardware being not standard complient while linux was really strict on that.

That is why I think the problem lay somewhere with Xorg or nvidia driver.




If you look at my GPU i/o you can see I onlt he 2 HDMI and two DisplayPort with one DVI. And I've tried any permutation possible of monitors cable and HDMi out put the result is always the same the monitor plugged on HDMI-1 appear as unknown. I could try with the DVI output but I don't have a DVI cable.

Or Xirg or nvidia want evry monitor to be on the same type of output or on diffrent type.

I'm not sure if I explain the right way.

Multihead setup on linux is a nightmare of config.

Quoting: sterkyI think for league not to change the set resolution in config, you need to add this parameter
[General]
Width=2560
Height=1440
UserSetResolution=1

Anyway, i see you also have a g-sync monitor, so if you are planning to use g-sync in games, you will need to disable those other screens for gaming time... the problem is that for g-sync to work it has to cover the whole screen, but multiple screens will make it virtually a lot bigger than one screen. Better explained in reddit.

So maybe it would make sense, to write a script that will turn other screens off and back on, then make it a macro with if you have gaming keyboard then it might have buttons for that or if not then just assign as keybind.

UserSetResolution=1

is already set in the config file. for the rest I don't use G-Sync at the moment and Xorg is syncing on the 60Htz monitor for V-sync anyway even if I set up th v-sync to the 144htz monitor. So any V-sync is disabled.

Also LoL is the only Windows sofware with that behavior at the moment. I have an other game with a strange graphic behavior but I put that on the game age from a time when multihead support was really uncommon.

Hmm strange then.
Also running 2 or 3 screens (one is tv, so not always enabled), have been playing league for years with multiple monitors in linux and i have never ran into this kind of problem =)

Looking at your xorg.conf, it's strange that you have 3 screen sections defined there, maybe could try removing all but Screen0 and then rebooting?

This is how it looks in my xorg.conf file.
xorg.conf