Wifi is fast on my desktop but extrememly slow on my phone

[AC Question]

Don't really know if this is the place to ask but my desktops internet speed is really fast, almost instant. My phone on the other hand connected to the same wifi is barely usable and stupidly slow.
For some background on my wifi, In my house I have a bt home hub 5 which uses the phone line to connect. There are about 3 routers/boosters to increase the extend the signal around the house. They are all named the same and have the same password so phones see it as one network, they also use the same wifi channel.
My theory is that my phone constantly is switching between each router and doesn't know which to connect to, In settings it only shows one network and not each separate router.
Is there anything I can do and what is the problem.
Thank you in advance

 

[Rukbat]

Put the phone on the hub that the desktop normally connects to, to eliminate the possibility of a bad antenna or connection in the phone. See if that helps. (If it does, the phone has to go in for service.)

Make sure that the hub's (connect to it using a web browser on the desktop) wifi encryption is set to AES, not TKIP or TKIP+AES. Some ROMs have a problem with TKIP.

Go to speedtest.net (first with one, then with the other) to get the actual speed (it's approximate, and varies from use to use, but "around 20mbps" and "around 5mbps" are different, 20 and 19 aren't). What appears to you to be a big speed difference may or may not be.

As for "what is the problem" - any one of at least a dozen possibilities. Try those 3 tings first. (Create an account here if none of them work - but read [GUIDE] Troubleshooting Wi-Fi Connection Problems first.)