Stuffing too many items into a bundle through commands will cause the capacity bar to overflow.
Steps to reproduce:
Use command:
/give @s minecraft:bundle[minecraft:bundle_contents=[{count:99,id:"minecraft:shulker_box"}]]
Hover over the bundle
Expected behavior:
The capacity bar overflows.
What actually happened:
The capacity bar does not overflow.
Note:
The bundle in the attached picture is 99 diamonds with max_stack_size:1
Relates to MC-259587.