Configuring session timeout for Remote Desktop Services web client (HTML5)

Is anyone aware of a way to customize the session timeout in the remote desktop services web client (HTML5)?

An issue our users have been experiencing is if they are in a long running remote desktop session and they experience a disconnect, clicking the "reconnect" button on the pop up they receive doesn't do anything. 

They also can't navigate back to the main menu to select their session collection to reconnect. 

The fix is they need to click refresh and log in again, it appears that the cause is that the users' login session to the remote desktop web client has timed out. 

Ideally, we'd like to customize the session timeout to be a long value so they could get through a whole work shift without their existing authentication session being timed out.