Assumed you still have the “old” image for the tag in your local image cache.
Inspect the old image (for the repository having the tag <none>) with docker image inspect ${image id} --format '{{.RepoDigests}}', then use the returned value (=the RepoDigest) without the wrapping [ and ] charachters in your docker run command or docker-compose.yml instead of the image:tag.
If you don’t use docker-compose yet, it is highly recommended to use it.
update: bloody forum markup is interpreting <none> as html tag which make it invisible - had to wrap it in backticks to keep it visible.