Hi @tboston,
Which notification approach did you choosed in your setup? Centralised or decentralised?
Did you activated the Checkmk Notification Spooler and did you configured it that your remote sites forward the notifications? Plus did you opened port 6555 in your firewall setup that the remote sites can send their notifications?
Please read about the differences here → Distributed monitoring - Scaling and distributing Checkmk
To troubleshoot it you can have a look at this there you’ll find described the different logfiles that you have to take a look at. → Distributed monitoring - Scaling and distributing Checkmk
Hope I can help you with that information.
Greetings Norm 