I created a new page hero the same way I have done it before but the header is not in center. It appears bottom of the container.
The only thing I did differently is that I made my blog post with guttenberg this time. Under the same category are two older posts that I have made with page builder and they get the same issue. So all 3 posts in that category get this probleem.
Awesome. Glad to be of help.
As a note the Duplicate Post plugin is real handy, not just for posts and pages, if you go into its settings you can select Elements making it easier to create header variations – i always use the New Draft option.