Inconsistent Shortcode rendering
The issue is kind of complicated. What happens when a Shortcode is embedded in a Post/Page is that the CiviCRM-WordPress plugin goes into "Shortcode Mode", parses the Shortcode and returns the resulting markup to the page.
However, if any action is taken via a Shortcode, a query string is appended to the URL and CiviCRM-WordPress goes into "Base Page Mode". The relevant code that tries to sort all of this out (and which has been present in the plugin since before I started work on it) is here:
Now, one of the results of going into "Base Page Mode" is that the entire content of the Post/Page is replaced via a filter on the_content which means - for some layouts and some themes - that the Post/Page is no longer rendered as if the Shortcode were present.
I realise that the current behaviour may now be the "expected" behaviour. Hopefully people can test the PR and let me know what impact (if any) it has for their designs.