Plusnet Hub 2 with TP-link powerline adapters

[#1]

After having my Full Fibre 550 installed recently, I wanted to get set up to the Hub 2 with a pair of TP-Link TL-PA4010 powerline adapters. After having these plugged in, the speed of any connection (ethernet to the router, powerline connection or WIFI) to the router drops to between 50-100mbps.

After removing the powerline adapters (unplugged from wall and router), factory resetting with a manual configuration and rebooting the ONT, the speed returns to normal (300+) then after 5-10 mins drops back to between 50-100mbps permanently.

I have also had an openreach engineer come to the premises after the install, who re-spliced the fibre connection to the ONT and believed there was no issue.

I do work for Plusnet so the entire situation has just massively confused me. I have read a few forums that state that the Hub 2 doesn't work with mesh systems but unsure as to why the issue remains permanent after unplugging the powerline adapters. From what I can understand, I don't believe it to be an ONT issue so could it possibly be a faulty router?

Anyone have an idea as to what could be causing this issue and how can it be resolved?

[#2]

Well for a start those powerline adapters only have 100Mb ports , so anything connected via them will have a max speed of 100Mb, and most likely less than that.

[#3]

After the problem initially started, after a quick Google search I found that the max speed of the adapters was indeed 100mbps, so I decided not to use them. After removing them from the setup, and rebooting/resetting the ONT and the router, the speed of normal ethernet and WIFI is still capped between 50-100mbps. Any idea what could be causing this?

[#4]

First of all, forget about any wifi speed tests for the moment.

Check the ethernet cables from the ONT to the router and from router to PC used for speed tests. Make sure they are cat5e or better i.e all 8 cores are connected. IIRC the Hub 2 has a speedtest built in , try that . If not then use speedtest.net