My new ISP Zen agreed to send an OR engineer to check why my line didn't reach the expected speed (according to their remote tests my line was able to sync at 70-71 Mbs, while the actual speed was 63.8 Mbs).
Long story short, the engineer after a couple of hours, said that he had to replace the old socket with a NTE5C and he advised me to disconnect the wires that were bringing the phone line to my bedroom (and I said yes) in order to have only the wires going to my living room.
At the end, you can see in the 'line_new' picture, I gained a few Mb and I also see less CRC and ES, so happy days.
Now, the engineer will report back that there was nothing wrong with the 'external' line, then Zen will want to charge me: fine by me, but I wanted the opinion of the expert users in this forum to understand (the two pictures shows my line status before and after the engineer visit) whether the problem was really just the fact the I had wires also in the bedroom and by disconnecting them the engineer fixed the line ??
Or there is something else, and in case I can dissent from the charge...