Understandable! I'm not sure what might have changed on our end but will talk to the team. 
Similarly, it feels like there needs to be a decision made about public apps and authenticated endpoints. I'll provide an update here as soon as I can!
UPDATE: I must have missed the announcement, but this was an intentional decision made in response to an internal security audit. It looks like the breaking change went into effect November 19, so it's been about two weeks now. I've included a blurb below about potential workarounds, but you can also make a post in the original thread!
Public app users will no longer be able to export PDFs with images hosted on separate domains. All other components will be included in the PDF export. We recommend moving your publicly hosted images to be hosted on the same domain as your Retool instance. For example, you could use images that are natively uploaded to the Image component, stored in Retool Storage, stored in Retool DB, Base64-encoded, or stored in an S3 bucket.