for the past year i have had my skin with slim arms, but today it changed to classic and it is not changing to slim. no matter what i do, my skin and arms dont change. on hypixel other people told me they are having the same problem

My skin isnt changing at all no matter what i do. for the past year i have had the same skin and it had alex (slim) arms. today all of a sudden it switched to steve (classic) arms and my skin wont change. i tried restarting my launcher but nothing happened. for the past hour i have been trying to get my slim arms back. i have heard that other people are having the same problem. please help me because i really dont like the classic arms