In reply to a post by MrSaffron:

Zen is NOT using CGNAT

Ok, I wasn't too sure.

In reply to a post by MrSaffron:

The most likely explanation if poster is not seeing this variation when they do a ping string from a PC, is the DoS protection on the Fritzbox When using a test connection is may not have been up long enough for the DoS protection to kick in.

That might explain the odd issue I had after 10 days where I would see packet loss ever X hours.

Its a shame the FRITZ!Box doesn't let the user add an IP / domain or a trusted list to bypass that feature.

Paul