Streaming tiles not updating in real time anymore

I've a custom app that pushes rows of data in a streaming dataset. It used to work just fine in the past but since a couple of days the streaming tiles (like a gauge) do not update in realtime any more. When I wait long enough(minutes) or refresh the browser it just works fine. I tried to find what was the cause but no success.

I now just tried to create a streaming dataset in the Power BI Web UI with just 3 fields named f1,f2 and f3 of each data type. Next I took the powershell script from the dataset and pasted it in the PowerShell ISE and ran it. It shows exactly the same behavior as my custom app is already showing for days. The gauges do not update in realtime anymore....

So if even the above example gives me errors, what else can I try ?

Thanks