OBS screen dimensions all messed up when recording fullscreen

[Sensayuma]

For some reason, my OBS' dimensions when recording fullscreen applications get warped towards the right edge and it's super annoying. This is what it looks like in OBS, see how the fullscreen application seems to leak into the preview?

 

[Suslik V]

This effect is commonly called the "infinity mirror". OBS captures itself too.

If you want to exclude OBS own window from the capture then you can set the option in OBS Settings > General > Hide OBS windows from screen capture

If you have second display device (connected to the same video card) - move OBS window to it.