This doesn't apply if you are connected via wire (Ethernet), but I've just discovered that a Wii-Fi connected mobile phone is causing issues in the house.
Its not stealing all the bandwidth, but it appears to be a hardware issue disrupting the WiFi when Bluetooth is enabled on the mobile.
As soon as BT is disabled, speeds on both the mobile and all other Wi-Fi connected devices immediately shoot up.
I am using a 2.4Ghz WiFi connection, the same frequency that BT and some baby monitors operate on.
This is not tied to a particular model of mobile device if you look here, but the offending device is a Chinese Meizu Android.
It has been reflashed with the Lineage OS (formely known as Cyanogen), so it's not a dodgy firmware doing nefarious things.
Anyway, just a heads up.
