My new uggs are stiff at the calf part.?

ok i got my first pair of ugg boots. they are supper comfy but there not as soft and flexible at the calf part. there stiff. when i took them out of the box they stood straight up. my friend has a pair and hers flaps down wen she takes the off but mine stays straight up. and they are a little bit tight but hers are loose and thats how they were wen she got them. Hope u can give me some answers. soon. :) :(