Only a few players received messages due to a bug in the previous update. This has now been fixed, I'm sorry for the inconvenience.
From now on, I will also include a 1.12 compatible version with more or less the same functionality as the newer versions. This version will be named BetterSleeping-1.12 and will also be statically named each update. Currently all features are included, except for disabling phantoms (duh).
You can grab the 1.12 compatible version on GitHub. Look for the jars called BetterSleeping-1.12.jar.
Once again, my apologies.