Recently I upgraded to an LG 2560x1080 75Hz Ultrawide monitor connected via DP 1.4.
When the monitor was in 60Hz mode I had full rez but when I noticed that MSI Afterburner still reported 60Hz I changed it to 75Hz but then Redout went into some sort of low resolution mode which sometimes persist to my desktop when exiting the game.

So my question is how do I get the full rez in 75Hz?

Specs:
Intel i7 4770k, 16GB DDR3, RX 570 4GB

Nevermind, I solved it by selecting another resolution in the options and then going back to 2560x1080.
Still, I have to redo this every time I restart the game, which is pretty annoying.