Had BT fibre for ages now, well over a year. It's been fine up until the past month or so. The bandwidth is complete trash whenever someone is watching Netflix or even YouTube. Makes it totally impossible for me to play video games.
I've phoned support and complained explaining the issue thouroughly, explaining the latency/ping and when it happens, etc. and I don't think he had a clue what I was talking about. Told me he would run some tests and that was about it, despite me requesting them to send out an engineer. Seems totally pointless to carry on babbling over the phone to someone working in a call centre.
Tried using 3 differnet routers, including a TP Link, and adjusting all the possible settings. I have mild networking experience so understand most the available settings. Tried monitoring & changing channels - doesn't fix anything. Tried an ethernet cable - no difference.
Screenshot of pinging Google (18.104.22.168) to show the fluctuation.