I am noticing this strange issue. The embedded FB Newsfeed on my website is only being shown if users are not logged into Facebook. This happens both on Desktop and mobile and in all browsers. It was created using FB page plugin and used to work properly.

So I recreated a new one, a simple HTML test page with just the plugin. It works only if the user logs out of Facebook! Otherwise, an error is given if any user is logged in on the same device. It's not because I am logged in as the page admin. Even a regular user.

See this please: https://www.theweddingsite.com/test_fbfeed.html

Logged in... an error is given:

Logged out... news feed loads successfully:

Can you please help? Thanks