I am using Blender 2.82a, Win 10 64-bit.
Using Render Region (Ctrl B) with Cycles, I was able to get white corners on the region and re-scale edges to modify the region after creation.
Now, for some reason, there are no corners or edge re-scale marks on the region, just a red dashed line.
Did I turn off the editable region display inadvertently?
you need to have a camera in the scene and it needs to be selected
i know. it makes no sense
you can have a regular view render region separate from an in-camera view render region but to tweak either you need a camera object selected
Yeah, I didn’t even know you could tweak the render region border that way until I read this. I was thinking the original poster accidentally disabled an addon that added this functionality or something.