When you scroll through the items in a bundle with the scrollbar, it shows an item inside the bundle sprite, sandwiched between the bundle_open_back.png and bundle_open_front.png. This item shown here in the bundle "sandwich" does not have custom model data applied to it. It does have enchantment glint when applicable though.
[media]Observed Outcome:
The item in the opened bundle does not have custom model data applied to it.
Expected Outcome:
The item in the opened bundle should have custom model data applied to it.
Steps to reproduce:
Join or create a world with commands enabled
Download and equip the attached resource pack
/give @s carved_pumpkin[custom_model_data=2]
This is NOT a duplicate of MC-275504 as that report talks about the bundle_open_back.png and bundle_open_front.png sprites themselves, not the item displayed within the opened bundle.
Can confirm:
[media]