Are you willing or able to free range at all? That will give them some space. Get a tape measure and measure the length and width of the coop (the building part) and also the run. It doesn’t look like he has much room to get away. Adding a few hiding places can also be helpful - lean some...
Leave them be and let them work it out. If your birds are < 1 year old, you have a cockerel and pullets. They’re working out their flock dynamics. If the hen is an adult (> 1 year old), she may be teaching him some manners. Unless she’s drawing blood, let them be.