SSL Issue With Buddypress

Hi all,

This is not in relation to any WPMUDEV plugins or themes but more a general issue that, after hours of searching through Wordpress forums, I still cannot find an answer for.

I'm running a Wordpress/Buddypress site with roughly 6,000 members. I'm using a "Let's Encrypt SSL Certificate" on the site combined with Really Simple SSL plugin and the SSL Insecure Content Fixer plugin.

This has properly secured the site itself and it passes all the browser checks to show the site is secure. That part is good.

Unfortunately, any page, status update, group or forum that contains user or staff posting link with only http vs https it many browsers through up a server verification warning because the site is SSL but the page being loaded contains external links that are not secure.

Additionally, when users try to post links via the Buddypress Activity Plus plugin the image from external links shows in preview but will not show when actually published to the activity stream if the URL being shared is not https.

Anyone have experience with this? Facebook can preview and link to http all day long while having https secured site. How are they able to do this?

Thanks in advance for any help you might be able to provide.