It may be that there is now some noise on the line that wasn't there before... BT's line tests do not necessarily pick this up.
Have a look at your ADSL connection stats on your BT hub and post them here.
Run the speed test at http://speedtester.bt.com/ and post the results - this will give your IP Profile.
Do the quiet line test (with a wired phone on the master socket) dial 17070 option 2 and report a fault (don't mention Broadband) on 151 if you can hear anything at all.
Fault with your line possibly? You will have to look at your home hub statistics to see what is going on.
If you look at other posts on this forum, you will find how to do this.
A large number of errors or disconnections will force to into a banded profile, with a lower speed.
can you post the adsl stats from your router may need to 'show detail' to get all stats (if hub enter 192.168.1.254 in your browser and navigate to adsl or use a-z, if netgear enter 192.168.0.1) are you connected to the NTE5 master or test socket or somewhere else?
Do you have any phone extension sockets in your home?
Have you tried the quiet line test? - dial 17070 option 2 - should hear nothing - best done with a corded phone
it looks like you have had reset/disconnection problems which have resulted in your speed dropping and the knock on effect is your profile drops. You are not capped from what you have posted
Someone may then be able to offer help/assistance/suggestions to your problem
My BT Hub Settings.....
Uptime: 0 days, 0:40:21
Modulation: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 5,472
Data Transferred (Sent/Received) [MB/MB]: 2.01 / 13.38
Output Power (Up/Down) [dBm]: 12.5 / 19.5
Line Attenuation (Up/Down) [dB]: 28.0 / 23.0
SN Margin (Up/Down) [dB]: 11.0 / 17.0
Vendor ID (Local/Remote): TMMB / TSTC
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 1 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 6 / 0
FEC Errors (Up/Down): 0 / 2,603
CRC Errors (Up/Down): 0 / 80
HEC Errors (Up/Down): 0 / 74
All line tests were ok.
your connection time is only 40mins - have you been resetting the hib or has it been resetting on it's own? Your noise margin is high at 17 as normal about 6 which is also suggesting disconnection problems.
Do you have any telephone extension sockets in your home as I am not sure what you mean by extensions - like phone extension cable or pwoer extension.
your profile is low due to your disconnections and is not capped