Varying Fibre speeds on different devices

[#1]

I've been with Plusnet for about 3 weeks on 300Mbps FTTP. I'm very happy with the speed to the house as, standing next to the router, I am getting speeds of 294Mbps on my phone and 305Mbps on my iPad. But I get only 70Mbps on my 2-year-old Lenovo laptop. The router is at the front of the house but our living room is at the back and there my speeds are around 235 Mbps on my phone but vary wildly between 22Mbps and 140Mbps on my iPad and my laptop. The laptop is the one I use most and it rarely gets above the 45Mbps I used to get with Sky (using powerlines). 

I tried searching this forum and the post here seems to have described the same problem. The fix was to ensure that the devices were using 5Ghz. I have checked in the router settings and it looks as though they all already are. My family have other devices but I haven't checked them all yet.

Can anyone suggest what I can do please to get more (consistent) speed on my laptop and iPad in my living room? Thanks. 

[#2]

The distance between your router, it’s immediate surroundings i.e. is it in a cupboard, mounted on an outside wall, positioning of it’s antenna ect will all make a difference. Using 5Ghz will reduce the range quite a bit as will the construction of your property

I too have a Lenovo laptop of a similar age with much the same performance, not surprisingly it performs much better on 2.4Ghz at that sort of range.

In my case living in an older bungalow with solid brick walls as opposed to a modern property with plasterboard and baton walls doesn’t help.

My solution was to use an old router (TP Link Archer VR900) as an access point connected to the main router by cable. This is located in the loft as near to the centre of the property as possible. This gives me excellent WiFi coverage on both bands in all locations within the property. I suppose it depends on your property, knowledge, ability and whether you’re willing to spend money on a solution.

A note of caution locating a router or access point in the loft is wide temperature changes and in some modern properties the ceilings may have foil backed plasterboard which would rather defeat the object !