No joy is to say that the VM doesnt get imported and I dont really get an error - I go to the tasks and dont see more than in the previous post.
However, I've just upgraded to the latest xen-orchestra docker image, xo-server 5.120.2 & xo-web 5.122.2 (xcp-ng is 8.3 beta) and it seems to be working better, at least via xe vm-import
Great product anyway, will keep on using it