I’ve seen this in my flock of Japanese quails. Guess bob white is about the same? A roo can be aggressive if she refuses him, but also get fixated on her if she has a different color than the rest. Can you arrange for a cage within the cage, so that they see each other? Then try to reintroduce in a few days. make sure they have several hiding places then. The hen separated needs a friend or two in the smaller cage. But it could as well be that you don’t have a good rooster. Being beautiful is not a trait that keeps you alive in my flock, so I have sent a few off for not being gentle when breeding for instance. young roos can take a bit to learn, but at about 4-6 months they should really know to let go of the hen when done, and not chase them around as well. I watch the interactions often and sometimes for hours when I see issues and select the kindest birds to keep. Doing that I started to be able to keep multiple Roos in the flock, with varying hen to roo ratio depending on the age-mix in the flock. A few old hens keeps the tempo down and seems to protest to the roos in an education manner. A flock of birds in the same age calls for trouble, then the Roos don’t get their education and you really depend on inheriting a kindness from mum and dad. This is just as in chickens, but you seldom hear it, and seldom see it if you keep small caged flocks. I keep mine in a shed-like pen about 1.7 x 2.5 meters, on the ground, have 28 birds, 4 roos within that. It’s an absolute joy to watch them. Do stay and see what happens, and separate the roo instead if he doesn’t have an acceptable behavior.
