I am unsure if this is the exact problem I had a while back with certain programs, but in case it is, try this:
If you are using a Geforce GPU, go to your desktop, right click, and bring up Nvidia Control Pannel.
In manage 3D settings, look for Antialiasing - FXAA, and if it's on, turn it off.
See if that fixes your issue. Alternatively, if Antialiasing if offered up in the in-game settings, if the option is available, switch it to another mode, like TAA. I can't remember if it's an option for the game.