Edit: Have you solved the problem? Your deletion time doesn't show, so readers could be confused by my reply, which I started writing at about 18:15 or later, when it was all there.
End edit.
Could you tell us the exchange please. It might help, as Zen have two different ways of conveying your traffic from the exchange onwards. (Backhaul).
I'm having a bit of trouble with
The Zen "Line Rate Data" stats for my connection quote a "Sync Rate" figure which is stated as being being "approximately 88% of the current Sync Rate", and a "current maximum download speed" that is around 97% of the "current Sync Rate". In practice the maximum download speeds are pretty close to the quoted "current maximum download speed".
So I am seeing download speeds that are consistently around 85% (=88% x 97%) of the sync speed.
The last two sentences seem to me to be contradicting each other, unless I'm misreading something. Or you've got in a mixup somewhere in trying to explain it to non-Zen users

.
(Also, but not really relevant, I think you mean a 40/10 package).
My broadband basic info/help site -
www.robertos.me.uk. Domains, site and mail hosting -
Tsohost.
Connection - AAISP Home::1 80/20. Sync 63679/13080Kbps @ 600m. BQMs -
IPv4 &
IPv6
Edited by RobertoS (Thu 08-Jun-17 18:28:05)