Ezzer/Eric are correct magicone.
If we (Openreach) have 'proved' that the MPF passes a Pair Quality Test, have fitted a RF3 filter and a NTE2000 SSFP, then there's not much else 'we' can, or more specifically,
have to do. The source of the fluctuations is external to our equipment, and 'we' have ensured our plant meets the relevant criteria.
As I've said before, because you are a lone soldier charity will only stretch so far.
, nudge nudge.