Your IPv6 is working! More seriously it seems
www.facebook.com is local and facebook.com is in the US - maybe without the WWW's you get the USA and it redirects back in the browser.
C:\>tracert www.facebook.com
Tracing route to star-mini.c10r.facebook.com [31.13.90.36]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms my-router
2 12 ms 11 ms 12 ms lo0-central10.pcl-ag02.plus.net [195.166.128.183]
3 15 ms 11 ms 12 ms link-b-central10.pcl-gw02.plus.net [212.159.2.166]
4 11 ms 11 ms 11 ms xe-10-1-0.pcl-cr02.plus.net [212.159.0.198]
5 11 ms 11 ms 11 ms ae1.ptw-cr02.plus.net [195.166.129.2]
6 * * * Request timed out.
7 11 ms 11 ms 12 ms po102.psw01c.lhr3.tfbnw.net [74.119.79.107]
8 12 ms 11 ms 11 ms 173.252.67.149
9 11 ms 11 ms 11 ms edge-star-mini-shv-01-lhr3.facebook.com [31.13.90.36]
Trace complete.
But my original comments were about iOS and Android apps and I have no idea what site they access, I haven't bothered to investigate. On my mate's Sky ADSL the apps are always slow to refresh and often don't load pictures/video. The website on a laptop works fine.
plusnet unlimited fibre 80/20 since 2 Jun 14 / Sync 6th Nov: 58,280/10,784 kbps with G.INP
16 years UK broadband (Since 1999 ntl:cable trial), Asus RT-AC68U & HG612 - BQM - Flash Speedtest - HTML Speedtest
Edited by jchamier (Sat 06-Aug-16 10:21:50)