You can't leave your bed when sleeping.

Actually you can by clicking on the bed. Perhaps I need to work a bit more on that feedback.

Yea I noticed you can leave the bed in the moments before you fall asleep by tapping on the foot of the bed. That would explain why clicking on the head of the bed is the only way to actually sleep in it at night. This works in multiplayer too. The time span of sleeping is only seconds to daytime so can't think of reason why want to get out of bed when sleeping, but can understand before sleeping if was mistake.

It's only the head because I wanted it to match regular Minecraft. Perhaps I'll fix this as well to make it a little bit easier.

This has been fixed, we now have the same button that is used for PC.