Beds become invisible and NOT function

I tried to place a bed like this (see the image I included).

It is okay right after I place a bed, but soon (I don't exactly know how long it takes) it gets invisible. This happens only at this particular point of my world. As I guess, wooden stairs are causing this problem (never mind, who knows?).

The real problem is that not only it becomes invisible, but it doesn't function as bed after it happens. For instance, the bed doesn't work as my respawn (HUGE trouble!). However, I can still bounce on the bed (which means it's there), I can even break the bed as usual and it drops itself. It's so weird, please help.