There is a case where images published to Discourse through the WP Discourse and RSS plugins can be broken. This can happen when the full post content is published to Discourse with the WP Discourse plugin and the WordPress Classic editor is used for publishing the post. It can also happen with posts pulled to Discourse with the RSS Polling polling when the
Truncate the embedded posts Embedding setting is not enabled.
The problem happens when Discourse attempts to download images that have been added to the post. If downloading the remote image results in a markdown image tag wrapped in HTML tags, the image will be broken.
If posts are being published from WordPress, the issue should be solved by switching from using the Classic Editor to using the Block Editor for publishing the posts. If this is not possible, or if it’s not resolving the issue, a workaround for the problem is to prevent Discourse from downloading the remote images.
If know the domains that the remote images are being published from, you can prevent Discourse from downloading these images by adding the domain(s) to the
disabled image download domains site setting:
If you are unsure of all domains that are being used, you can prevent Discourse from downloading all remote images by disabling the
download remote images to local. Note that disabling this setting could result in broken images on your site. If possible, it is better to only prevent downloading of remote images from specific domains that you control.