Progress bar disappears before microflow has ended

It's possible to show a progress bar for long running microflows and we're using it with microflows which we expect to run longer than a 20 seconds. Very nice, but we've some issues with these progress bars. The progress bar dissapears sometimes before the microflow has ended. We know that because we log everything between microflow activities. Problem is that after this progress bar is removed, no client communication in the microflow triggers. At some point, we're running a java-action. We want to show a message if it's succeeds and show an error if an exception is thrown. But that doesn't happen. We cannot reproduce it and it seems that the progress bar disappears after 1/2 minutes and we saw this issue in two different mendix projects. Anybody? Edit after research and desperation: Seems like this issue doesn't occur when we call the microflow asynchronously. The active polling mechanism works in such a way that the progress bar doesn't disappear.
1 answers

Yes you're right. Calling asynchronously fixes that. The reason that the dialog disappears is most times that a router / proxy or whatever closes the connection. The client then thinks the server is ready but in fact the server is still busy but the connection is closed by same hub between the client and server.