It may not be the right thing to do, but cutting an ethernet cable and using the other 2 pairs to send the phone line with VDSL2 can cause bad interference to ethernet and vice-versa? I have 4 pairs on phone cable. If I connect the modem to the other disabled line, i still get some low SNR and internet works. Phone is mute on that line, so no shorts.
Snr is being inducted on the other cables.
I know I wouldnt get the gigabit ethernet, but in some cases, we need to sacrifice some things.