ADSL barely syncs

A few weeks ago I was having a few disconnections so had my SNR reset to 6dB from 3dB which seemed to help for a while. Recently my ADSL would no longer sync at all (tried two modems with the same outcome). I managed to get connected (barely) with the modem connected to the test socket after tying 4 different micro-filters with SNR back to 3dB. My modem error rates seem to be through the roof reaching the millions (they do reset each time and I have never seen them this high before). Could the low SNR be causing this many errors or could this be caused by interference? Cannot think of anything that would be causing this. Wondering if someone cold take a look and offer some advice. Stats below. Thanks.

Uptime: 0 days, 0:01:25

DSL Type: ITU-T G.992.5

Bandwidth (Up/Down) [kbps/kbps]: 1.200 / 11.702

Data Transferred (Sent/Received) [MB/MB]: 23,61 / 387,20

Output Power (Up/Down) [dBm]: 12,8 / 0,0

Line Attenuation (Up/Down) [dB]: 20,4 / 37,5

SN Margin (Up/Down) [dB]: 5,4 / 3,0

System Vendor ID (Local/Remote): TMMB / ----

Chipset Vendor ID (Local/Remote): BDCM / IFTN

Loss of Framing (Local/Remote): 18 / 0

Loss of Signal (Local/Remote): 2 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): -

Error Seconds (Local/Remote): 1.381 / 0

FEC Errors (Up/Down): 0 / 137.168

CRC Errors (Up/Down): 0 / 0

HEC Errors (Up/Down): 0 / 0

Running with a three db target SNR is always going to give grief if the pair isn't squeaky clean, and if there's a hint of interference, it'll suffer more than most too. For starters I'd be asking to be put back on a 6db target, speed is nothing without stability.

Yes that's exactly what I have asked them to do to see if it solves it. Thanks for the response. Could someone from Plusnet possibly check ticket 86837355 please?

Thanks.