Minecraft's Skin Issue

There's something wrong with the character's skin, when I put a skin and then choose Alex's body, the legs always look bugged, but when I choose Steve's body, the character's legs are normal, except for the arms, cuz most skins I use have slim arms, but that's not the main issue. The major problem are actually the pixels, those form the legs, they seem out of place. Can y'all fix that?