ADSL Speed Drop - Increased Contention?

[#1]

The raw ADSL speed reported by my router has dropped from approx 3500-3700 kbps down to approx 2200 kbps. The line has been fine at around 3.2M according to the Internet speed test for the past few weeks without any line drops, so I'm a bit puzzled as to why it suddenly (AFAIK) dropped to just over 2M yesterday after I moved the router and accidentally disturbed the ADSL connection.

The line has very little noise or errors with the SNR stable at about 2.6, so I'd expect the usual 3.2Mbps on the speed test  which I've had over the past 6 months.

Perhaps I only noticed the drop yesterday, and it's been that way for a few days? Has anyone else noticed a drop in speed?

[#2]

Things are improving, but still a mystery...

At about 6pm yesterday my Internet connection dropped, when it came back the SNR margin was 8 but the speed was the same as before at about 2.2M.

2.2M is about what I'd expect with the SNR at 8, will see if things improve.

Anyone at Plusnet reading this, please don't make any changes without contacting me first?

Thanks