Some skin packs are not showing items

The bug

 

Some skin packs made by Minecraft doesnt show items in the hand or capes, im not sure why this happen but i think that is a transparency problem.  i saw this bug in two skin packs that i´ll list below

• Journey to the west
• Redstone specialist

 

 

How reproduce the bug?

 

To reproduce this bug is very easy, just need to use any of the skins that are in the skins packs above, put an item in the hotbar or equip a cape or use a elytra and will be able to see the problem