Chickens are prey animals and they are hard wired to flee any threat, including the hand that feeds them ... especially when coming from above and attached to a large human.
FWIW, they will be a bit like this until closer to lay. The hormones of laying seem to calm them down and they generally will be more calm. BJG are not known to be flighty. We’ve had BJG for a couple of years, both male and female, and they are pretty calm overall.
Keep trying to get them used to you. Some feed in your hand, etc. by the time they begin to lay you will likely have some friendly birds.