I created a new skin, but my other custom skins become that same skin.

Hello, today I have an complaint about a glitch that happens to custom skins. So I had added a custom skin to Minecraft and it works perfectly, but when I try to add a new custom skin to my skin collection, it sets not just the new skin, but other customs skins to that same skin. Any skin that was made in the “Character Creator” part is fine, it only affects custom skins. This has been going on for maybe 1 or even 2 months now and I don’t know why. I don’t know if anyone else is having the same problem but if anyone has any idea on how to fix this, please tell me or get this fixed please. Thank you to who ever is reading this and I hope you have a nice day/night.