Application window closing and showing user disconnected

Using the HTML5 interface. After opening an application, after about 25-30 seconds the application window closes and the console shows the user disconnected. Opening the app again resumes the sessions but once again disconnects after 25-30 seconds. Looking into the logs, I found the following in the html5gw log after each time I connected. The disconnect happens always happens in 25-30 seconds, never more or less, like it's on a timer somewhere.

Wed Feb 05 16:45:57 2020 - Sent IdleServer to 'USERNAME_OMITTED_FOR_SECURITY'
Any idea on what would be causing this? Didn't seem to have a problem when running 17.0 but have now upgraded to the latest build 17.1.0.2 (21679)