ENDIAN Firewall - Some question on proxy service

I work with the 2.4 release of Endian Firewall.
I have some trouble with the proxy service.
1) With the transparent proxy enabled, I see, in the system graphics, a gradually increasing commitment of RAM (seems normal to me); but every morning at about six o'clock use the RAM drops drastically and then gradually start to grow up till the next morning. Is it normal? I think that the decline in the use of RAM occur because something or someone clears the cache: is it so? If yes, where or how I can set this?
2) Again with the transparent proxy on, if I try to open the 'proxy access graphic', the page returns me the message "No information available." Is it normal?
3) When I change the proxy settings, and finally select "Save" button, a window informs me (spinning circle) that the system is going to apply the settings but it never stops. I have to force to close the browser window and reconnect. What's wrong?
Confident in a generous and patient response, waiting, I salute you.