[João Pedro]

Ok, from what I understood disabling FX Bypass stopped the weird screen splitting (I see weird because the other half loaded with artifacts). Though a problem still remains: the Chroma Keyer doesn’t show correctly on the preview, not keying out the selected color, but renders just fine.

Edit: I solved it, a huge thanks to everyone who helped!

In case anyone was wondering, this is what I mistakenly called a “bug”: