The bug
Item frames with the 'Fixed
' tag set to true can be placed inside of other blocks, and do not break.
Steps to Reproduce:
Get an item frame with the proper tag(s) applied:
/give @p minecraft:item_frame[minecraft:entity_data={Fixed:1b,id:'minecraft:item_frame'}] 1
Place down an end rod with a glass block in front of it (these blocks are not necessray to reproduce the issue, they just make it clear/easy)
Place the item frame down on the side of the end rod which faces towards the glass block
→ ❌ The item frame is placed inside the glass block
→ ✔ The item frame would not be placed as there is a block in the way
Screenshot:
[media]
Can confirm