I too am having similar issues. I am using the GeoEvent extension to stream data to attributes of one of my feature layers. To test, I am streaming pseudo-random data. I set the "layer should be refreshed periodically" section to 1 second in the General tab of the layer properties, and I set the Cache option to "Don't cache any data locally." By clicking a point and examining the pop up, I can tell that my data is streaming to the layer, but the layer itself is not updating. To be more specific, I mapped the random attribute to unclassed colors, and the colors only change sometimes when I zoom.
I noticed this post is getting a little old, so I wanted to see if anyone has made any progress, figured out if there's another setting that needs to be adjusted, or otherwise found a way to stream real time data (at least one point per second) to ArcGIS Pro (or any other mapping tool) such that layers like heat maps or unclassed colors will update in real time.
Edit:
I am also trying my application in ArcGIS Online. If I click the ellipses for my layer, and change the refresh interval, the layer updates as expected. The application is limited to 0.1 minutes, but if I type 0.01 minutes as the interval, the map appears to update with that rate. However, once I hit enter or remove my cursor from the input box, the layer stops updating and the checkbox indicates the layer is no longer refreshing. If anyone knows if it is possible to permanently overwrite the 0.1 minute limitation in AGOL, that could also be helpful.
