That BT hub will also have a couple of unsecured networks for the use of other BT subscribers. (Unsecured, but you need to log into them once connected). I think you'll find that your machine is attempted to connect to those preferntially because they appear to be "open". It can become a right PITA
Two choices - one is to log those two BT connections in the device software and list them as "blocked" - not sure if thats possible in Android though
The other is to simply turn them off - for that you need to log into your BT online admin account and do it (you cannot simply do it from within the BT router software), or else call BT support and get them to do it.
The downside is that if you optout of the BT network sharing system, you won't be able to log into anyone else's BT hub