Kentico v13.0.151

Error message showing up on page builder even though page builder seems to be working correctly.

This page does not work properly as your browser may be blocking 3rd
party cookies and/or the system may be incorrectly configured for a
multi-domain environment.
See our documentation for more information.

So the iframe can load in the presentation site and I can work with it fine.

3rd party cookies are allowed. The presentation and admin are in the same domain with the admin site set in a virtual directory of the presentation site as per Trevor Fayas’ advice.

I’ve tried all the various cookie settings as per the docs.

Are there a list of cookies I can check for to see which ones are failing? Or a way I can dig deeper into the issue?