Project Cars Forced Windowed Mode and Low Res?

So for no clear reason, Project Cars is stuck in a forced windowed mode and a lower resolution.

I launch the game and it's windowed. Alt+Enter doesn't do anything. I only get an error sound (Windows 10) when I try. Then in the game's settings I can't seem to bring the resolution up past 1280x720. It's supposed to be 1920x1080. Also, windowed mode is enabled. Of course I switch that to off, but upon restarting the game, which it forces me to in order to apply the settings, the problem starts all over again. The settings just reset to 720p and windowed. What could be causing this? It's the only game of a few I've played in recent days that does this. Everything else is fine.

I have exactly the same issue as of today. 1280x720 and not all settings on highest as before.

My pc:

Intel i5 4690

8GB ddr3

AMD R9 290

1920x1080

Windows 10 Pro 64 bit

Strange! Perhaps the game broke itself with the latest update?

@Amster_G: Maybe. I have no idea how to fix this. I tried disabling "Virtual super resolution" in the Radeon Settings app but it didn't make any difference to the game.