Quick update that I have posted also to the chromium bugs. This is Linux solution! This command in terminal fixed my problem:
xrandr --output DP-2 --rate 240.0 --primary --mode 2560x1440Run xrandr with no arguments to see what output you have connected etc. and fill your resolution. I have added the command to run at startup. This sets the rate correctly so the browser can then run with it.