It is unusual for this to happen after being put in a larger cage. Do they have a nest box? If so, I would remove that and see if it makes a difference. If not, I’m not sure why he would have started doing this. It may be the larger cage has him wanting to mate, and the female isn’t interested. In that case, it’s pretty normal for this type attack to happen. But honestly, you may not be able to put them back together. Some birds are not compatible as mates and possibly now that they are breeding age, they don’t want to be together anymore. It would be better to let the female be in the large cage for a few weeks without the male, and then slowly try to reintroduce them. But if he attacks at all, I would split them up and not try them together anymore.
Thank you for asking Lafeber,