Several things you can try, friend gets this all the time in a world that I'm his guest
Move the selector circle around before clicking spawn
Have a friend join. (Its odd but a guest can get in while you cant) guest Run around you shoot a gun near you, possibly break your bed
Archive the world, load a non online world back out dearchive and try again
Clear cache, start another game then come back
Curse at 7 day God's
When he leaves for the day he leaves the base as it seems to happen more often when a fire or forge is going near you when you leave. Might just be him but if he can hear a fire noise when spawning in more likely to not let him spawn...