Are you by chance using two monitors, one of which is not 144 hz? As soon as I unplugged my older monitor everything worked. Here is my askubuntu qeustion I opened: http://askubuntu.com/questions/745980/dual-monitors-60-hz-and-144-hz-games-can-only-run-in-144-hz-if-i-unplug-the-60
Are you by chance using two monitors, one of which is not 144 hz? As soon as I unplugged my older monitor everything worked. Here is my askubuntu qeustion I opened: http:// askubuntu. com/questions/ 745980/ dual-monitors- 60-hz-and- 144-hz- games-can- only-run- in-144- hz-if-i- unplug- the-60