Images and iframes not loading

I have no idea what I’ve done here, but since restoring a backup from a few weeks ago, I can no longer use images or iframes in my lovelace?? Images are not recognised via full URL (hassio.local:8123/local/image.jpg etc) and if loaded to any card they fail. Iframes also fail to load, whether http or https.
I’m sure this is security related (I can no longer open via my duckdns.org address either) but I can’t see what exactly? Its almost like an ssl certificate has failed so all communication is blocked. Any ideas at all what could have changed??

Updating to add:
When accessing via internal IP eg 192.168.0.X HA shows as unsecured, I can’t remember if it was this way previously? Any ideas on how I can check the external IP of the RPI3 running HA to check my firewall rules?
As it stands, any iframes I try to load just load a window with my HA in it for some reason