I installed this a few weeks ago without any problems, unlike 3 other firewalls I am testing. Up to now, the tray icon was animated with red and green crosses and plusses running up and down it. My settings are to allow this icon to be animated (I have looked!) and the settings tell me that there is nothing else to be done but it does concern me that this animation should suddenly stop for no discernable reason.
Please do mention the OS, other security services running like AVs etc.
Have you tried to reinstall CIS and see if it solve this?? The animation normally functions well when ‘Show Tray Animation’ is enabled by right clicking CIS tray Icon. And yes, the animation will appear only when you open a site or download something. However, if you are connected to internet but not surfing there will be no animation. (I am sure you are aware of it as you have already mentioned that you test firewalls).