HH3b - Incompatability Smart TV and Netflix

There was a long thread on the BT Care forums that has recently been closed so an explanation was not provided.
Anyone have an idea why a HH3b wouldn't work with some Smart TVs and Netflix?
The solution was to send out a HH3a which unless they have been fixed since I last checked, have issues with VPNs and port forwarding.
I went with Tomato flashed ASUS anyway so not too concerned but as there has not been a firmware update on the HH3b since 2013, what has changed upstream to affect this?

The Netflix error is UI-113. Netflix works on all other devices as do all other streaming services on the affected TVs.

Edited by smouty (Mon 22-Feb-16 14:06:49)

Nobody have an ideas?

There is some more info in this article - http://www.ispreview.co.uk/index.php/2016/02/bt-broa...