They have though, pretty frequently actually. Everytime the Hub Discs get an update there's a change log, only sometimes when the actual hub gets updates they will tell us, like here:
(1 of the many examples) maybe @DanielS can help.
On my Hub it changed all the Line Atten and Sig Atten to higher numbers... Upload got really slower
FYI - you are not the only customer to experience slower speeds and higher line attenuation after firmware upgrade to SG4B1000E020 in the last few weeks - see these two posts:
It could be a coincidence, but perhaps there is a connection?
Sorry to bring up an old post, but we're also currently battling an issue which may be related to this router / firmware upgrade. We cannot pin down when the issues truely started, but likely around the time this firmware was updated. BT are sending us a new router, so we will know if it is definitely this causing the problems.
Just noticed this post Ive had issues for the last few weeks now with v slow speeds on all our devices even when only one is connected yet speed test to hub says Im getting 61Mb. Just put old hub on and speeds back to what they should be with numerous devices connected at the same time
Guess a call to BT is called for in the morning