I have one that dose that too. He is 8 months old and still sleeps like that ! Mighty Mouse looks like a wet dishrag flung on the clothesline when he roosts. He seems normal in every other way, super good with his pullets and healthy as can be.
The problem with sleeping like that is it left his face exposed when we had -50 windchill and he was frostbitten badly. He lost about 1/3 of his wattles and there are still bits of his pea comb sloughing off.
I'm wondering if it is inherited behavior as one of his sons is doing it too.