There is a bug that when you're from 1080p reso and then switch to 720p reso, the hero selection screen will not crop properly in windowless mode. If you're from 720p and switched the game to 1080p without restarting, the hero selection screen size will still be the 720p size and will not automatically resize to 1080p.

Please fix, its annoying to restart dota 2 everytime i change resolutions.