I have BT full fibre with speeds at the router of 970mbps (result as tested through My BT app). WiFi at the router is in the region of 330mbps Mobile phone and laptop.

I have directly connected a laptop to the router via ethernet but can only get speeds of 100Mbps, there is a problem as I cannot change the Laptop network adapter / properties  / speed above 100mbps Full Duplex. From the BT console it appears that the ports on the hub are set to Gigabit.

I have a PC connected in another room via ethernet / powerline but can only get speeds of @ 50mbps, The network adapter is up to date with driver and set to 1.0 Gbps Full Duplex.The powerline as shown above firmware updated today. WiFi using mobile phone from same powerline returns very slightly better speeds. I have another powerline same model which returns similar WiFi speeds.

I am concerned with the differential between the newly installed full fiber / powerline speeds, prior to the "upgrade" I was receiving better speeds through wifi / powerlines with potentially 1/3 the initial speed.

Is there anything else that could be done to improve these speeds?