Speed test sites showing BT as ISP?

[#1]

I know PN is part of BT but why are speed test sites (as well as IP location ones) showing BT as my ISP?

It's never happened before. And in the last few weeks, opening nearly every website as well as Youtube has been extremely slow. Could this be a reason why everything has gone to pot recently?

Thanks.

[#2]

Probably due to the move to their new network. In order for them to do this, they seemed to have used ip addresses from other parts of the group, and it takes a while for the ownership to show correctly on some sites.

[#3]

Thanks Mustrum. And how long is this whole transfer to the new network going to take? - I'm sure it's already been a few months.

Also, has PN notified it's customers about the move and is this one of the main reasons why webpages including YouTube are taking a while to connect and load?