When you login as the test_user, you only have access to the BT speedtester, and DNS won't work for other sites, but sometimes you have to enter the ip address of the speedtester to get it to work.
But I wouldn't bother at the moment, too much playing around in the first 10 days and the exchange thinks you have an unstable line. I see from the stats, you have a line attenuation of 33 dB which puts you about 2.5Km from the exchange. Also the current target SNRM is running at 9dB which is why your sync speed has dropped. Ideally you'd like to sync above 7392.
Be patient - in the first 7-10 days your profile can vary, throughput tests can also be very variable especially at peak times, but the last BT one is somewhat spurious. I'd ignore the BT speedtester for the moment. As long as your sync is holding, if the PN profile at the member centre is consistent and the PN speedtester gives good figures at that time of night, all should be ok. You don't have any significant errors either.
Keep an eye on those router stats though. If that sync drops and the target SNRM goes up, you may have a noisey line. If you hear any crackling or other intermittent noise on the line, phone your line rental provider faults when it is crackling (151 if BT), don't use autotesting, go straight to an adviser, get them to confirm they can hear the noise and log it as intermittent. DON'T mention broadband otherwise you'll get the runaround back to the ISP.
Best of luck.
