I meant to mention. SteemIt adds the attribute rel="nofollow noopener" to all outbound links. The nofollow directive tells Google that the link is potential spam.
So, if you had a robot that wrote a thousand comments with links to your web site. Google is likely to categorize your web site as spam.
Having a dozen nofollow links into a web page is considered normal. Having thousands of inbound links with nofollow tags is a good indication of spam.
The nofollow tag reduces spam, but it has a side effect.
What appears to happen is if I created a web page; then created a steemit post with a link back to the source. Google would interpret the nofollow tag to mean that SteemIt was the source and that my web site was the copy.
But if you paraphrased your steemit post, Google is more likely to recognize your web site as the original source.
RE: Link rel="canonical"