According to https://www.blocked.org.uk/ there's an SSL timeout with Sky and Virgin Media.

I'm not sure how reliable that tool is, testing with ThePirateBay.gd gives "dnserror" for all the ISPs except one, but only adds a blocked since time for one (BT).

It's always worked for me, on all the big five. I've just tested it now (having disconnected from my PIA VPN) and it worked fine.

The VPN works too (obviously). I do sometimes find that switching to TCP (which should make it slower due to overhead) makes it faster, but it's ISP dependent, which implies the OpenVPN UDP traffic is being throttled.

Probably for the simple fact that it's a VPN service...so they blocked it with the "porn filter".

Works fine for me.

blocked in Oman as well.