I have a function that summons item frames using /execute summon item_frame run function ... and then sets them up correctly, including their rotation. This specific case works in singleplayer, but breaks in multiplayer, probably related to differences when changing the rotation in the first tick of the frame existing on a server vs single player.
The general bug also happens in single player though.
I also tested 1.21 which also has the issue, but offsets the item frame in a different way.
There is also MC-181110, which was resolved as Invalid at the time, but actually doesn’t happen like this anymore. In 1.21.5, the hitbox in F3+B matches how the item frame appears visually, and in 1.21 the hitbox appears like the item frame appears in 1.21.5. So the whatever changed between 1.21 and 1.21.5 now makes the hitbox and visual appearance consistent, but neither were correct in the first place.
Steps to reproduce
Facing north, place glass blocks and an item frame in this shape, with the block sticking out to positive z:
[media]Run the following command:
data modify entity @n[type=item_frame] Facing set value 3b
Expected behavior
The item frame is now placed on the glass block facing towards you:
[media]Observed behavior
The item frame is offset such that it’s aligned with the bottom of the block, but its orientation remains unchanged. It renders fully inside the glass blocks, making it invisible if this was a solid block.
[media]This is just a visual glitch, leaving and re-entering the world will fix it.
When not changing between ceiling, wall and floor, and just between different wall facings, there is no visual change.
This is the visual appearance of the same issue in 1.21:
[media]
This is how it ends up looking in my game btw, looks very funny 😄
[media]