To identify why WP content may not be appearing correctly on FB use https://developers.facebook.com/tools/debug/ 

Facebook will retain any content until it is forced to scrape the page again using this tool.​

Showing FB feed on WordPress

Using FB feed as recommended by Thrive.  See: https://developers.facebook.com/docs/plugins/page-plugin/ 
FB generates a custom code for the specific page where the plugin is required and the code for the plugin.  Paste the code into a Thrive WordPress Content element wherever it is required.
A bit clunky and has to use scroll bar in fixed height.  Alternative and more attractive is POWR plugin.

Posts from the MyDewsbury FB Page