Fullscreen mode still rapidly switches between monitors

[Newbytee]

Your system information

• System information from steam (Steam -> Help -> System Information) in a gist: https://gist.github.com/Newbytee/7f4dd300c32e80b199680fcace991ffd (I have Steam set to Swedish, sorry)
• Have you checked for system updates?: Yes
• Are you using the latest stable video driver available for your system? Yes
• Have you verified the game files?: Yes

Please describe your issue in as much detail as possible:

The behaviour is exactly the same as what's described in https://github.com/ValveSoftware/Dota-2/issues/2435. However, I'm still experiencing this with the latest version of Dota 2. I don't know what I could be doing wrong. Disabling one of my monitors while Dota starts up works around the issue and I can play just fine.

Steps for reproducing this issue:

Same as https://github.com/ValveSoftware/Dota-2/issues/2435