I placed three beds on a full block, and is surrounded with acacia blocks, both full and half slabs. There's a three block space above my bed

I just don't understand how it says that my bed is obstructed. I tried taking out one of the beds, and placed it in the middle of the room like this. Sleeping in any of the two beds on the sides will result in this visual glitch. However, sleeping on the middle bed would not show any visual glitch whatsoever.

Another problem that the three beds have is that they are "obstructed" for some reason, and I only return to my original spawn point after death. What do I need to change in my bed design?