Hi there,
This isn’t related to the dynamic CSS. It’s happening because of an incompatibility with Offload S3. The Header and Footer builders store all the data used to display content in the_content
field of a WordPress custom post type.
When you enable the “Rewrite File URLs” setting for Offload S3 it will take CDN urls and convert them to regular media URLs anytime a post is saved. This is why if you save and reload the builder the image no longer displays, and also why it doesn’t show on the front end. Offload S3 is setup to do the inverse, so when the post is prepared for display the URLs are converted back to their CDN version. For some reason this is failing in the footer builder. The Header and Footer builders does load things a bit different than a regular post. We’re not doing anything unconventional or outside what the WordPress APIs allow for, but Offload S3 just isn’t setup to handle this way. A few things were changed in this update to prepare for Global Blocks which is likely why it stopped working in 2.0.
Offload S3 is not a plugin we integrate with, nor can we guarantee support for it. However, there may be a workaround we can implement to get this working. I would need you to provide SFTP (or FTP) credentials to continue.