Help with platy behaviour

[Nicolina142]

Cycled tank 5 female and 1 male mixed platy. Male platy seems to be aggressive towards one of the females, not letting her swim and socialise around the front of the tank. She's submissive towards him not pecking him back like the others do, but he rams her, chases and blocks her so she can't swim away. She can come to eat at feeding time, so no issues there and she comes out when he's busy else where and looks well otherwise. I don't know what I can do or is this normal? Help. I can upload a video if need be.