Skin Model Bug

When I logged on today I noticed that my skin's model was the Steve model. This was odd because I've always had an Alex model (with slim arms) and never changed it. I also have not changed my skin in a few days so this was unusual. I logged onto Mine craft's website and changed my skin and making sure I pressed the slim arms model. I logged on and had no luck, I still had the classic model. I tried changing my skin multiple times making sure to click the slim arms model but it would never work. I even tried changing my skin in the Mine craft java launcher. Every time I did this I would still have the classic format. I really hope this can be resolved since it was quite frustrating.