I was misled into optimism. The line 2 was very sickly yesterday, out of respect.
Modem was cycling through the training steps trying to get to showtime for a good part of the time. As of 12:36 UTC today approx
it has now recovered and is perfect again. So we have an intermittent severe fault. On Friday afternoon, AA saw a report of an "exchange fault" and "refer to BTW" that you saw on Friday. I have asked AA if they have an idea what that was all about; too soon to expect a reply, and they will probably be swamped with serious problem questions after the long weekend with the bank holiday.
So all good for the moment. The stats are perfect. There’s no sign of any HCD even. At that point this morning it very suddenly jumped back to being perfect. As if there had been someone out there working on it, just not based here. Perhaps AA had booked something on Friday that took effect just then. All known pictures available. The logs show chaos yesterday and before.