Removing items from item frames from wall near ceiling causes them to go missing.

I've searched Item Frames and Item Frames Missing objects and I haven't found anything similar to what I'm looking for.

I have a wall of Stained Brown Clay that is 5 high with various item frames on various level of the wall. When I wanted to take the items off the ones on the 5th level near the ceiling the items dropped but I was unable to find them on the ground. I was able to remove the ones never the bottom level close to my floor. I was removing gold armour and a gold sword. Also since the update I had 2 item frames with missing items I can't remember what they were though.