Kevin,
I have tried different HDMI cables (including 4K cable) with no effect.
I went to Graphics Options→ Custom Resolutions and defined a custom resolution 2560×1440, 32 bit, 30p. I see it in the list, I cannot understand how to apply it.
When I input the necessary information in the dialog I see no attempt that driver tries to apply this resolution (e.g. flickering or something). How can I force the custom resolution? Could you please share step-by-step instruction?
Thanks.