Hi
We like to watch c4 /All4 and BBC iplayer , CH5 etc
We have been using smartsdnsproxy service to
enable us the access the uk on demand channels for 18 months and it’s worked fairly well but lately we been experiencing issues with pausing and loss of sound and picture issues particularly when using All4 not sure why it seems to All4 that’s affected more than the other channels.
Anyone any advice and possible solutions or an alternative DNS

These things seem to go in phases. Every alternative "works great" until it doesn't - presumably because the broadcasters "catch up" and make a few adjustments and then the providers catch up and it's all good again.
Even free VPNs like Hoxx work...then not, then again.

Download Opera browser - https://www.opera.com/ it has a built in VPN (free). I open a new private window, enable the vpn - set it to Europe, then open All 4 - which works for me 90% of the time.

That's interesting.
I was able to add Beebs vpn to Opera some time ago when it proved impossible for firefox and I used that because the Opera one didn't work for me.
I just assumed it wasn't any good but having experienced "some times they do, sometimes they don't" with a few, perhaps when I tried I was in that 10% period.

I'll have to remember to try again if my usual sources don't have something.

I've been through quite a few and for the past 6 months I have been using Getflix DNS and it has been working flawlessly on all devices in the house, computers, mobiles and Apple TVs