Character Creator Skins Show Steves When Using a Custom Resource Pack

Issue popped up that seems distinct from descriptions of other skin display bugs. Character creator skins display as steve in game despite showing as loaded properly in the main menu. There was no "Failed to Load" message. The issue also applies to the other player's character creator skin showing as steve. Steve also appears in the character creator screen when editing the skin and accessories, with no effect when customizing the skin. Shown is how the slim alex arms are equipped with no effect.

The issue only started to appear after many multiplayer sessions in an established survival world, hosted on my PC. The issue did not appear in a freshly made creative world, and only appears in the survival world. Tested multiple times with the same result. A custom uploaded classic skin continues to work as normal and is visible by the other player. It seems that character creator skins wont display on my screen in that world only.

*Edit:
It seems that a third party resource pack is causing this issue, after looking more closely. (It is a pack that shows chunk borders). Not sure if this is a bug with the game or the pack, since it shouldn't affect skins. Regardless, this issue should probably be closed.