Dude, see the suggestions by @dippywood the latest version is 21.02.1
The broken package can be held back with
echo "linux-dtb-current-sunbix64 hold" | sudo dpkg --set-selections
@IgorPlease do not think that your efforts are unappreciated - they are, and greatly so. I was simply concerned that the board status was not what I expected.
I also agree with the work-around - and thus me taking the builds and working out which would work for @robocone
I am also not adverse to providing workarounds when I can, and, as time allows, I will attempt to identify exactly where the problem is, and share same.
Once more, the efforts here are greatly appreciated (at least by myself) and I remain grateful for all of your efforts. If I can find the cause then I shall do so, but. for me. the 'free' is very valuable