I have two Harmony Hubs, both connected through MeiHarmonyHub. Both connections start correctly with the PI starts and usually run for a few days. For unknown reasons, one or both of the Hubs will drop "offline" with cryptic stack-trace error logs entries, usually stating "connection refused". Reconnecting does no good. Resetting the Hub does no good. The only solution which I've found is to stop and restart the PI.

Not a huge problem, but I thought you should know.