checked your logfiles but debugging was not enabled in authentication logs [:(] Tried to reproduce this with a timeout of 60sec, which worked fine for me.
This is how it works: With the first request you trigger the authentication window. After authenticating successful with the gateway, the authentication timeout will be counted down. If you're surfing in this very moment while the countdown is running to zero you'll get the authentication window immediately again. However, if you're just reading a website without sending any request, you do not need to authenticate until the next request is sent to the HTTP proxy. The countdown will start again *after* authenticating with the HTTP proxy.
My understanding was that the user will authenticate once and then -i.e after 60 sec- it won't request another authentication since the user is browsing and therefore it's already authenticated.I thought that the inactivity of the client for xx time (timeout define) will trigger the authentication for the specific client. Probably a stupid assumption. I am guessing I can increase the timeout so the authentication is not requested every 60 sec and solve that issue