As I've just PM'ed, so this is for others reading the thread, so far as I can see I have just cracked the ZyXel 1312 for dualstack IPv6/IPv4, despite having been told it has a ZyXel bug and there was nothing to be done.
I have had it running (though obviously unused for a few hours) since something like 1:45 this morning. See the two BQMs in my sig.
As supplied it was set up to go with my HG612, but for this exercise I have set it to full modem/router mode. I will need to speak to AA about that, and their master configuration.
I'm convinced your ZyXel is either faulty or your dodgy line is killing everything. Or both!
Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk.
Domains, site and mail hosting - Tsohost
Connection - AAISP Home::1 80/20. Sync 60000/15336kbps @ 600m. - IPv4 BQM IPv6 BQM
Edited by RobertoS (Sat 03-Dec-16 16:17:01)