Has anyone managed to tweak their VDSL SNR via the CLI on a V166 as per this article: https://www.draytek.com/support/knowledge-base/4800
It worked on my old Vigor but although the CLI command on the V166 says it's worked successfully it won't sync no matter how small the tweak (even 0.1dB)
It's really annoying as the V166 seems to set a higher S/N figure (8dB rather than 6.2dB on my old Vigor) resulting in a slower connection

Doesn't it also depend on whether the DSLAM equipment supports changing SNR?

What message are you getting?

As I said my old Vigor worked fine, I was able to tweak the target SNR down from 6.2dB to 4dB and keep a stable connection, so it's not a DSLAM issue.
Once the V166 CLI command is executed I get the same message as on my old unit - that the change has been successfully applied.
At this point it reboots, but it refuses to re-sync to the line, & if I then input an equal but opposite tweak to cancel out the 1st one it still won't sync!
A power cycle is needed (which clears the target SNR setting back to default) to get things back to normal.