Trying to figure this out. My current project is a pixel game at a window size of 480x270. Whenever I preview the game in its standard resolution- its fine, and behaves normally.
Whenever I try to fullscreen the game however, it slows to a crawl.
I noticed that this even extends to the default example C3 projects, as well as games in the scirra arcade.
I've tried all three preview modes in the settings (Popup, Browser, Dialog). All three previews still have this issue.
My machine is a VR-capable rig so I don't think it's a hardware issue. This problem doesn't exist on my C2 projects.