Chests render incorrectly in the inventory with this mod, not in the hotbar but specifically in the inventory. This may apply to other 3d blocks with multiple components but I couldn't find any other examples off the top of my head. This is using the 1.17 version of fabric with 1.17 versions of optifine.

Have you checked this doesn't happen with just OptiFine installed on its own? There's a chance this is just broken from OptiFine being a preview still