I'm connected to my virgin fibre optic router via tp-link powerline adapter with my ethernet cables. When i ping anywhere e.g google.co.uk or riot.de using the command prompt i get regular normal ping (around 38-42 ms) however constantly get request timeouts every 5-10 seconds. This is a huge pain in the ass when playing online games such as League of Legends as my screen will just freeze and not sure where to go from there. https://gyazo.com/ca584b9015dbd9d182a654644a15a487 There's a gyazo of a recent ping test
There are a large number of factors that could be causing this packet loss. Unfortunately because.your connection is quite fast its difficult to tell much from the latencies you are seeing.
The next step is to run MTR (winMTR) which combines ping and traceroute. If run for a fair amount of time it will show where the problem is as well as the extent of it.
I would postulate that your provider is using QoS/bandwidth pooling and dropping packets to slow down TCP connections and limit utilization.