Fill option not working.
Hi guys, I can't fill some of the faces of the cylinder, no matter what I do. Some work and some don't. I've attached one of the plans that I can't fill. I select the two edges and press the F key and nothing happens. To test this I move on to the next plank and I do the exact same process and it does work. I'm not sure what I'm missing here. Also, if I switch to vertices select in edit mode and I choose 3 vertices, the filling option does work (another example attached) but if I choose the 4 vertices it doesn't.