When cloning or moving an area containing item frames, they and their contents do not get moved, instead they seem to check the blocks they are on after the move and pop off if unsupported.
I would expect them to move with the clone command, trying to clone move an infinity room or redstone using them via block comparitors is currently a nightmare!
Linked issues
Comments 2
See MC-46122.
The clone command clones blocks only. Feature request.