sdl2-compat causes black bars

[Topey2X]

Changing the window size larger than the default results in sections of the game surface obscured by black bars.
This only started happening since Arch removed sdl2 and replaced it with sdl2-compat.

Game itself seems fine. Resizing smaller than the original size works as normal.

Version: 2.1.0 (although terminal shows 2.1.1 DEV ?)
(Sourced from AUR, but I don't think that's the issue).