I believe I maybe just figured out the problem and I'll release a patch tomorrow. If you have the game locked to 60 fps (likely in your graphics card settings), try setting it to 165. I'll have a setting for this released tomorrow.
I made a Vulkan build. I'm not sure if that will change anything, but give it a try and let me know how it goes. If you both have AMD graphics cards, this could be the issue. I read that OpenGL doesn't work well with AMD GPUs.