I have notice that the upstream will almost pause, drops to sub 1mbps sometimes then back to full again , i have only seen this happen around the peak time on the tbb speedtest ,as it appears to only affect single threaded, In testing i ran a single threaded file upload using FTP and it wouldn't stay anywhere near the max throughput, it was yo yo ing , but at a quieter time it will upload at full tilt , so ? something is a bottleneck but for me this isn't really new, as i have been seeing similar since shortly after my service went live ,on and off for around 18mths , mainly sun & mon peak time
I read one of the REV k's rants and some of his customers where having issues , he put them on elevated traffic, and there was an improvement , yet btw were saying not faults ect iirc, if plusnet would for testing switch off their traffic shaping for a week or so, if it still persists then they could put a number of those seeing issues on elevated to see if that showed improvements or not, process of elimination maybe is what is required, or some truths from plusnet, because whatever is /are the reasons for it it has been allowed to go on for too long already, plusnet saying we don't know or it isn't our fault, ain't good enough