Recently I have started playing Minecraft 1.15.2.
I have recently discovered an issue with item frames.
This is what happened for me.
I placed an item frame.
I destroyed the item frame.
The hitbox stays behind while it disappears in-game.
I am not sure if it is just me or it is a bug.
I also happened to be on a vanilla server I hosted just for me and my friend.
Unable to reproduce, are you using any kinds of mods on the client (like Optifine) or the server (like Spigot or Paper)?