What broadband package do you have?
The issue is with the Phones and IPads, it slows down considerably. Full Fibre 900 with BT Halo 3
If other devices connected by wired Ethernet show no slowdown it would suggest a WiFi limitation. Are you using a BT Smart Hub 2 with no Discs? Have you checked whether all devices are on 2.4GHz or 5GHz?
We have a disc upstairs. How do I check what GHZ they are on
If you login to your router from a web browser, by default 192.168.1.254 you should be able to see all the connected devices and how they are connected. Unfortunately I have a BT Home Hub 6 o can' give you detailed instructions.
Looks like they are on both.
I presume some are on 5GHz and some 2.4.
5 is faster but has a shorter range than 2.4 both obviously share bandwidth amongst al the connected devices.
You can download software such as "WiFi Analyzer" which you can try in various locations and it should give you an idea of WiFi strength in each location for each band. It may also detect neighbours WiFi and show if that is sharing a channel with yours, in which case it might be worth changing channels.
I m not sure how the WiFi disc will show up or what the software will tell you about it. If it is connected to the SH2 by WiFi you might find that moving it, or changing orientation makes a difference. Hopefully someone with with experience of that disc will comment on this thread.
I know in our study my wife gets 822Mb/s to her laptop but in our bedroom I often struggle to get WiFi but I use wired Ethernet usually.