BQM Check for Gig1 please

I'm unconvinced, Mr Pearce.  There's packet loss visible across the day and through the night and for that length of time the OP would struggle to saturate the 50 Mbps upstream, plus the nasty latency profile matches exactly what you'd expect on an over-subscribed segment of VM's network.  It's possible that there's two problems - one causing the packet loss, and the other being the capacity constraint that's causing the latency issues.

From years of experience looking at these, I'd suspect at the level of over-subscription the BQM shows, VM will deny on their grandmother's life that there is any problem of capacity or utilisation.  And if that's the case and they're not prepared to admit the BQM shows a problem, then the problem will never be fixed.  If they do admit there's a problem of over-utilisation, then the years of experience tell me the promised fix date has been plucked from somebody's fundament and means nothing.

As for LexLuther, I'm afraid if I'm right (and I'm not always*), then you will have to live with that sort of performance unless you (a) have a better ISP alternative, and (b) are willing to play a game of hardball with VM to be released from contract without penalty.

* Just 99% of the time.