I received the following anwer from a PulseSecure support engineer after I created a case and we did some tests: "As I verified the connection broker, load balancing and the any RDS scenarios are not supported with HTML5 access. So it is be due to these reasons that you are facing the issue of disconnecting. After replicating in lab I see that it works fine without the use of the connection broker, load balancing and the RDS"". What we found, is that a RDS session (even on a RDS farm) stays stable if a browser is not started in the session. No disconnects happen until we lauch a browser (IE or Chrome) within the RDS session. After we launched the browser we are frequently facing disconnects. PulseSecure support says that this issue is due to using an RDS broker. For me its strange that the session (even when using a broker) is stable when I'am not using a browser within the RDS session. ... View more

What I also noticed is that when I do a html5 session to an ip-address (not a dns name), and this RDS server is not part of a RDS farm, then the connection is made without problems.... I doubt if it has something todo with dns and SSL Certificates on the concering RDS servers ... View more