Yeah. That could have serveral reasons:

1. Steemit.com itself uses no xml sitemap in combination with Google Search Console (makes it harder for google to index everything in time)

2. Like me you are still a new account. Which means our post are only shown for a short time in the tags, when they are relatively new. So when the google bot doesn't crawl the page in this timeframe the possibility to getting indexed early reduces.

3. And of course not having links to this article from external websites is also a reason, that it is not yet indexed.

4. When you have few followers, you dont show up in many feeds (example: https://steemit.com/@mark-dahl/feed (just pick any username). Reduces also the probability of getting indexed.