I have a strange issue on my home network connected through BT home hub 6 which has only occurred recently. I can ping some sites no problem and get an IPv4 reply. However on some others, it resolves the address in IPv6 and then hangs. If I ping -4 it works OK.
This happens on multiple devices (Windows 7, Windows 10, Ubuntu, Android ) so seems to be something on the hub or at BT.
e.g I can ping bbc.co.uk but not google.co.uk
If I use the Windows 10 laptop (which shows the symptom on my network) on someone else's network or on my phone hotspot then it is OK.
This causes browsing issues e.g on www.bbc.co.uk it starts OK but then when the page calls ibbc.co.uk it hangs. If I ping ibbc.co.uk it displays the IPV6 issue (resolves the address and then hangs).
If I disable IPv6 on the client then everything is OK. At the moment this is my solution, so I guess I can stay that way but it feels like something is wrong somewhere.