The main question is why do you think you need greater than 55M? Unless you are doing a lot of streaming of multiple HD TV simultaneously then the speed is not really required and 55M will be ample. You can always opt for the 55M package and move to the higher package later if it doesn't suit your needs. Your speed drop will be due to a fault which needs to be fixed, either by Plusnet if you stay with them or BT if you move.
I think you are going to see progressivly slower speeds, whichever provider you use. This is caused by crosstalk from other VDSL circuits, which reduces the quality of the transmission path.
The more VDSL users that connect to the cabinet, the slower the connections will become.
Copper wires were never designed to carry high frequencies. It only take as couple of adjacent unbalanced pairs, to generate a lot of crosstalk, which will affect the connection speed of your circuit, and others.
There is nothing you can do about this.
I dont need greater than 55 TBH, but i am paying at the moment for 76.
I am still of the opinion that there is a fault somewhere because, as i said, the speed dropped off overnight, however, the stats i have been shown have shown there is no fault on the line as my speeds barely scrape into the minimum i should recieve.
I totally understand that and i'm certain that it will happen over time but i am convinced it isnt that in this case.
Im windering if my speed is capped for some reason?
This tech is all a bit confusing to me 😄