> page refreshed automatically but no change in URL
It will just set a cookie and refresh to www.google.com (or www.google.yourtld). `safe=active` only manifests when you search for something.
No, I'm just saying it should be disabled in googler at the moment wherever you are, and given that users of googler should mostly be adults or at least have judgement, and googler is not visual, I'm not sure a safe option would be useful.
Actually, I connected to a German node of PIA, and went to check https://www.google.de/preferences. Safe Search is off.

Think of googler as Googling on a fresh browser without logging in to a Google account. Here in the U.S. at least, SafeSearch is off by default. See https://www.google.com/preferences. YMMV due to different laws in different countries.