Players in survival are unable to sleep when there are others in spectator mode. I would expect that they would be disregarded, however they have to leave the server in order for players to sleep through the night.
Although I think it's fairly self-explanatory, I'm apparently supposed to put step by step instructions of how to replicate.
1. Have multiple people on a server.
2. Have at least one player in survival and one in spectator.
3. Have player in survival attempt to sleep.
4. Find frustration in the fact that he can not.
Dupe of MC-47080