Looking at the stepped decline in DS SNRM, my gut feeling is that your connection has been affected by increased crosstalk.
The latest disturber, if it is indeed a crosstalk issue, may be sufficiently severe to cause Interleaving & delay to be now needed.
You may also see a worsening in QLN levels in your snapshot graphs.
QLN & Hlog data only update during the training stages when a connection syncs up, so those would be the relevant periods to look at.
As your DS Bitswapping levels are relatively low, I 'suspect' you may be using an older mode firmware version.
In comparison, your US bitswapping levels look relatively high
I'm not sure, but that may be due to the amount you upload & thus the heavy use of your connection.
The latest firmware version makes better use of bitwsapping, tends to allow DS FEC & is G.INP ready.
Generally speaking, you appear to have quite low error levels, so I don't suspect the speed reduction & application of interleaving is due to a line fault as such.
FWIW, Attainable rates do always appear to increase somewhat unrealistically whenever interleaving is applied.