Yes I think it's just what the Fritzbox does. It's strange that some days it's small and other days it shows up 40% loss (even overnight when no traffic). Switching the Zyxel out of brdge mode (without even resyncing) so that it is replying to the BQM always cures it.
See this one:
The period with no loss is where I switched the Zyxel's router in, then shortly after I switched the Fritz back in again, the loss came back but not as bad.
A couple of days ago I flashed OpenWRT onto the Fritz and obviously the 'problem' has gone. I realise I don't really gain anything as this packet loss on the BQM does not seem to affect my internet experience, but I'd still like a router that allows me to monitor my connection properly, which I now seem to have.
I can always flash back if I find any negatives with OpenWRT.
Edited by Glenn2 (Wed 03-Feb-21 13:40:21)