x2 possibly a juvenile molt. Space is tight though, I know plenty of folks are happy with these Omlet set ups but there simply isn't room in them for more than a couple of birds, so any behavioral issues gets magnified.
Your girls are still quite young, it probably looks big enough for now...
Photos of your set up?
Adding clutter to your run would help give lower ranked bird(s) some relief and hiding spots from being picked on. Additional feeder(s) would also help. https://www.backyardchickens.com/threads/a-cluttered-run.1323792/