Since v1.13.0.1 Beta was released, sleeping in a bed causes the view to float up rather than stick with the person sleeping. For example, you won't be able to see the cat sleeping on your lap as your view floats away from the bed. Happens on any bed placed anywhere.
Screenshot tries to show it.
There do seem to be other posts similar to this one, but the ones I've read seem to have been closed due to lack of feedback rather than a resolution. One mentions that the viewpoint is similar to sleeping standing up, rather than lying down; that feels accurate.
I have confirmed restoring the same world from a backup (where I'm 100% certain the problem never used to occur) still shows this issue, which makes it more likely to be a symptom caused by the latest update rather than something that has been manipulated in game?