The bug

A bundle which contains sufficient components as to render a durability bar will not do so. This is without a doubt related to the fullness bar which bundles also use.

How to reproduce

1. /give @s stone[minecraft:damage=5,minecraft:max_damage=20]

2. /give @s bundle[minecraft:damage=5,minecraft:max_damage=20]

Expected results

As both commands were identical aside for the item ID, both would have durability bars.

Actual results

The bundle does not.

Further notes

On this topic, a component to hide the durability bar (like what already exists to force-hide the enchantment glint), or vice versa, may actually be a useful addition.