Need help with huge packet loss consistently every 21m

For the last 6 weeks I've been trying to get Vodafone to fix this problem, it took them 3 weeks just to agree there was any problem at all. At best I get roughly 15 mins of good internet followed by nothing for 5m. 68~ times a day I get spikes for the last 4 weeks I've been measuring it for, except for 1 several hour window where it was clean after the service in the area came back online after it had been down through the night. Sometimes packet loss can be as low as a few percent, other times it's just a mess.
The ip changes every time I lose connection so large blocks of red are where I've not set the new ip and black is where I was just fed up and unplugged.

Live BQM:
https://www.thinkbroadband.com/broadband/monitoring/...

one of the worst days:
https://www.thinkbroadband.com/broadband/monitoring/...

One of the best days:
https://www.thinkbroadband.com/broadband/monitoring/...

That Live BQM is looking extremely ropey today...presume that they are actually assisting you now?

It's fairly self evident that your connection is broken.

Unfortunately they don't seem to know what they're doing, I've had to run my own tests. Mostly they phoned me daily to tell me they fixed it at first. They tried switching first hop somewhere else which didn't help. Cityfibre visited and said everything was really good and it was probably vodafones software.
So now I'm waiting for the expert team again, but apparently they don't work over the weekends and so another week goes by

Your BQM links are broken right now due to a bit on new site. We hope to fix this tomorrow. Apologies.

Links work again

I guess they finally found someone to fix it after 10 weeks. Can't wait for them to explain why it was broken

That's looking a whole world better.

Any clue as to what the issue was / what they changed? Presumably nothing local to you (router etc)?

They finally got back to me, they said a few vague things, something about a cable to 3 end users having issue. elevating to a higher team doing something to the street cabinet and adjusting the software. I don't know if he really understood it tbh and I think they might be avoiding saying who's fault it was, theirs or cityfibre. So I presume something was misconfigured at the point where it diverged to just the 3 of us in that cabinet? Regardless, seems like something that you'd think they'd be capable of catching in their tests.

Well in any event, the key thing is it looks to be resolved. Thanks for circling back 👍