Ugh, I thought the problem was gone but I had a couple of loss of syncs this afternoon again, not too long after emailing AAISP to request a DLM reset from TTB (which is pointless if there's still a fault). At one point my connection synced with normal downstream speed but only 0.5mbps upstream. I've changed the modem cable from a 'high quality' cable to a cheapy spare flat RJ11 cable, but I highly doubt that's the reason.
Prior to that I did a line test on CIX twice, first time it came back 'Test Inconclusive - Further Diagnostics Required - raise Trouble Report with OR' with a fault location 'DT' and asking me to do another test. Second time it says 'Line test OK. Dial tone OK'. I'm not sure what I can do at this point as I fear this is an intermittent fault that's just playing tricks with me. I'm waiting to see what AA suggest next.
This is what my connection looked like when it resynced during the problem again, until I resynced it with a change of RJ11 cable:
https://imgur.com/a/sKhShb9This is what my connection looked like after I resynced it again with a change of RJ11 cable, and generally what it looks like prior to the problem occurring (other than DLM banding and interleaving):
https://imgur.com/a/IQke66hLine test results:
On one final note, I did notice last night that my BT handsets lit up and for a second said "line cord error" (aka no phone line) then went back to normal. Broadband however seemed unaffected by that brief blip.
I hope this fault isn't going to be a complicated one to fix.
EDIT: AAISP have got back to me and said it does look like there's a fault on the copper side, and could try forcing an engineer out. I don't know if this would be an SFI engineer but I assume it may well be. I'm waiting to hear for an appointment. Fingers crossed they will find something conclusive and it won't require multiple engineer callouts before something is eventually found (like before at my old address).
This reminds me of my old address all over again
, just perhaps in a bit of a different way this time.