buildx failed with: ERROR: failed to solve: ubuntu@sha256:bbf3d1baa208b7649d1d0264ef7d522e1dc0deeeaaf6085bf8e4618867f03494: failed to resolve source metadata for docker.io/library/ubuntu@sha256:bbf3d1baa208b7649d1d0264ef7d522e1dc0deeeaaf6085bf8e4618867f03494: failed to copy: httpReadSeeker: failed open: unexpected status code https://registry-1.docker.io/v2/library/ubuntu/manifests/sha256:bbf3d1baa208b7649d1d0264ef7d522e1dc0deeeaaf6085bf8e4618867f03494: 503 Service Unavailable