Camellias
Shelter from the cold, dry winds and early morning sun. Buds and flowers can be damaged by cold winds and late frost. Dry weather can also cause bud drop, so water plant if necessary. (mine likes old tea leaves) They like a westerly or sheltered northerly aspect. ( mine is in a sheltered northerly position) Against a wall or in a woodland is also good. They like their roots cool and a lime-free soil.
Good luck
Linda

I suspect your Camellia is in an east facing exposed bed where the flower buds get hit by sunshine whilst they are frosted. This causes the bud to die and decay.