Same URL in multiple tabs, but only 1st gets logged. Why not all?

Hi all,
let's say I'm on a website, and in a new tab or window of the
same browser I'm opening the same URL anew.
But this time no logging of the URL happens.
Is this by design (maybe some kind of caching) or maybe a bug?

Tested with this URL: https://www.startpage.com/
and some others, but seems to me it happens with all URLs.

I'm using "debug 512" in config.
Environment: privoxy v3.0.21 from Debian repo on Debian 8 Linux amd64.