Nostalrius Begins - Quality wow vanilla realm (1.12)

When I set the refresh rate to 144 hz in the ingame video options the screen turns black for a second, but does not apply the change. 120 hz is working fine, but the game won't keep 144 hz.

How can I fix this? Or is this even intended?

bump

As far as I know the vanilla client doesnt support 144hz (even though it is available in the settings, assuming you have a 144hz screen). I too have a 144hz screen but can only utilize 120hz in game.

Have you tried forcing 144hz through the config file?