To put it simply, when going to sleep in a bed, there is a chance that pressing the "Leave Bed" button will not work. Pressing the ESC button doesn't work either.

When I try to fall asleep, say in a village, or a bed that I myself have placed, there sometimes tends to be a weird thing that happens when I try to leave the bed. Sometimes, whenever the I try to leave the bed, my character will lie on the floor. When this happens, you are unable to leave the sleeping state. Pressing the "Leave Bed" button does not work, and pressing ESC does not work, either. You can still run commands, however. The easiest solution I've found to this is to type /kill (your name). The game saved your spawn point when you went to sleep, so when you click respawn, your items will be there. This solution is only temporary, however, and does not work 100% of the time. I, personally have found a somewhat high success rate with this, but sometimes it doesn't work as intended. Sometimes your spawn point doesn't save for whatever reason, and you'll be sent back to the world spawn. That's all I can say for this issue.