ManofGraphene Thanks for your reply - you set me on the right path and it has now worked. It was obviously to do with the 6a settings as it related to downloading files onto it ...
I had 'install unknown app- allowed' BUT if you click on it there is a sub menu 'allow access to android/obb folder 'which was not allowed
I went through all the settings for the Vanadium app and the browser settings again - like many I am the sort of idiot who slowly hardens things but never remembers .
So I don't know what it was that allowed it to work but I
- turned on nearby devices and sensors in Vanadium app permissions
- allowed access to android/obb folder as above
- in vanadium browser settings >site settings>content>on-device site data = allowed
Once or other of these made it work
Lessons learnt
1/ If you incrementally harden things , keep a note of it (I'm too much of an idiot and I will never do that )
2/ Don't harden things if you don't need to ( I'm too much of an idiot and I will never do that )
3/ Accept I am an idiot
Thanks for your help in the right direction and I can now forget about it all until the next time