This has been a bug that's been in the game for years. Whenever I use a Texture Pack that is detailed and uses a high amount of pixels, it'll make a certain amount of items appear outside of your hand and EXTREMELY oversized. I just want this to finally be fixed so I can enjoy these Texture Packs again, it's been literal years….
Please edit your report to change the Affected Version to the version shown on the Minecraft title screen