Open a blueprint page - go to page information button and notice the Rollout button is missing. This must mean that its live copy inheritance has gone. (somehow) How can I put that back as an AEM author? Also if I am not an AEM author there must be a way in CRDxE
Rollout command on the blueprint page depends upon on whether a source is referenced by blueprint configurations.
If you create a live copy from a source page that is referenced in a blueprint configuration, then only Rollout option will be available in the page information.
Blueprint configs are available at http://localhost:port/libs/wcm/msm/gui/content/blueprintconfig.html
Rollout button is missing or disabled ? If it is disabled, Go to the livecopy page and the jcr:content where the cq:LiveSync config node resides. Check for the excluded pages and isDeep value. Adjust the excluded pages to remove the page where page is disabled and set isDeep is true and try replicate the issue again