Thanks for posting in Cloudflare Community! My name is Brandon, and I’m with the Customer Support team, happy to assist!
I’ve taken a look at your post here as well as your Redirect Rules and Page Rules, and one thing I will note is, using the “URI” or “URI Path” fields with a full URL is not a valid setup.
Essentially, using URI or URI Path is expecting the content after the hostname, so in this scenario, the URI would be /login. You can include the full https://pvafrica.site/login but it would need to be as “URI Full”.
Additionally, I’m not seeing where the site is being redirected to Facebook, so I assume that’s being done on the origin server. Additionally, Facebook itself would have to redirect the user back to the site in question - Cloudflare can’t control that behavior with URL options like Next-Site.