Search:

Please try.

Wordpress Admin > Classipress > Settings > General > Open Graph [ ] Representing site pages in the social networks.

Untick.

Please check.

Shortcodes Relating to ClassiPress
https://docs.appthemes.com/classipress-4-x/shortcodes-relating-classipress-4-x/

I use Front End PM Pro.
https://www.shamimsplugins.com/products/front-end-pm-pro/

Front End PM Pro works well with Classipress in my site.

Thanks @madmanc
I really appreciate your help.

Topbar menu > "+Signup" button

Please help to change the text from "+Signup" to "Register". Change hollow button to solid button similar to "Login" solid button.