I've reported it to Support on Monday but so far all they've done is run a pointless line test.
That pointless line test is something they have to do, battery faults always pop up when its wet but have no effect on single threaded speeds, or any speed issues tbh. HR faults on the other hand can. The first thing they have to check really is the metallic path, so until we all have FTTP that will no doubt continue. along with your own equipment and wiring of course. It also depends who your back haul is with, as IDNet use Zen and a few others. If there is a Zen pop in your exchange, or if you are a small satellite off the main exchange you may be connected to that pop. When I had single threaded issues which really only effect VoIP, torrents, gaming and video streaming really, it was a Zen issue and chatting with Brian sorted it out, after I found out who to talk to at Zen and the supporting information from TBB which IDNet were not aware of and I had no reason to expect them to be.
I have to say unless I see a issue I just leave it all alone these days, I'm not one for constant speed tests. Also the server that TBB uses for the test itself could be having issues, so many weak points in the chain. For myself its not worth worrying about. I will say though IDNet support has never given me issues they are always helpful and its better than the plusnet forum or hanging on the phone for 40 minutes at times. (My mother is with plusnet now and is having lots of issues and lots of very long calls!) Saying all that, I have no single threaded issues here (01243 area)