My function app is consuming event hub messages, but stops when not observed

My issue is pretty identical to https://github.com/Azure/Azure-Functions/issues/220, except this is supposed to be solved.

I have an IoT hub from which I get roughly 2 million messages evenly distributed per day (Plenty to keep my app active!) using the EventHubTrigger

My function app is doing the processing whenever observed in the portal, but when inactive the instance seems to die off and the events are piling up.

Are there still known issues around this?

Invocation info: WestEurope, 2018-10-04T14:08:42.749 Id=49049e91-c7cc-4966-9cae-3c1987b50426