Cape bug

Hello.. some time ago i noticed that if i have picked skin with cape (example: Minecon 2016)
[Not the capes from skin settings but the from marketplace!] and i fly (or walk it doesnt metter)
next to some player who have the normal cape (from settings example: pancape) my cape will bug and become same as his and for his client side his cape will change to mine.. Its really weird..

It actually do this on every version