Customizable Skins Won't Show in Servers or Multiplayer Worlds

All Known Info About the Issue:

Steps to Reproduce:
#1 Made a customizable skin
#2 Joined a server or multiplayer world
#3 Entered in the world as a basic skin ( Steve or custom server skin )
#4 Left the multiplayer world or server and came back as Steve in the main menu
#5 Switched to a different skin and then back to that same skin I entered the multiplayer world or server with and the skin was back to normal.

Observed Results:
When I use a customizable skin in a server or a multiplayer world, the skin fails to load and I show as a basic character such as Steve or another server character that the creators of that server chose to implement. Then when I leave the server, it will show up as Steve in the main menu, however, then when I switch from the skin I had used in the server or world, and then back to it, when I go back to the main menu, it is back to normal.

Expected Results:
When I use a customizable skin that I can create, I should be able to join a multiplayer world or server without having this issue.

Screenshots/Videos attached:

Notes: I also noticed that when I join a singleplayer world, nothing happens and my customizable skin loads without any issues. ( These are all the steps I mentioned at the top in one video, and yes, it's fast ).