After some thinking and debugging over the weekend I appear to have found the source of my problems and fixed my issue.
Drum roll, cymbal crash… it was a network problem, not ipv6 but ipv4!!
I use hassio, the new version of hassio uses hassos, to set the network you can reserve a DHCP address, create a network config file or use the nmcli in docker. For expediency I initially used the nmcli and set up my network stack. While this created a functioning install of hass, it wasn’t really functioning?!?!
So what tipped me off? Following a reboot yesterday I have started to see a number of internet integrations failing, I immediately suspected router issues etc but worked out quickly that the smoking gun was back with hass, while it had the correct network info it wasn’t working correctly. So long story short I followed the instructions for option 2 above and ‘bang’ everything is now functioning as it should.
I think there may be a problem with the way the host passes network details to the container with my version of hassio BUT this is an assumption rather than a position of knowledge and likely a glitch, however the hard coded method has resolved the issues.
Thanks to Robbie and others that have contributed