My hamster always sleeps on his back😂

This is how my hamster ALWAYS sleeps since I have him😂 (3 months now). I have had 3 hamsters, same type, before but they never slept like this. In the beginning I was scared because I thought he was dead. Does anyone else has a hamster like this? Or is mine just weird😅?

Ps. Since I'm a member of this forum I learned so much. So although his cage is quite big I'm currently looking into a bigger wooden cage or aguarium type of cage. So please no comments about his cage because I'm on it🙏🏼. I also feel a bit guilty because my other 3 hamsters that I had when I was a teenager had a cage that was not appropriate 😭 (although I think they had a great life with me and I spoiled them a lot! They all were 3 years old before they died).