After observing this new feature for a while, it seems the caret appears only for duration that the process or service connection is in an established state.
In this screenshot shows that Firefox and the print spooler service are consistently established
The POP Peeper app reaches out every 30 minutes to look for new mail. The connection is so rapid, I’ll never be able to examine its data - the caret appears in a blink of the eye and it’s gone.
As well, one would just have to have the Firewall page open and in sight all the time to watch for process activity.
Or perhaps I’m just not “getting” this new feature??