There is a bug currently where if you place a dragon into a Player Market Stall, when the person buys the dragon it will lose its stats. We are working on a fix, but in the meantime if you are a player who is running a stall, please remove your dragons if you have placed them there. I will let you know when it’s safe to put them there again.
Note that trading dragons directly is working fine as far as I know, it’s just putting them in stalls that seems to be broken.