Is anyone using a Custom URL in conjunction with sharing a Canvas instance with Catalog? We're having all kinds of authentication issues where we get stuck in a Discovery Page loop, and no solution yet from Canvas Support.
Our intent was to use Catalog to provision non-school accounts, and self-enroll in Canvas courses we feature in Catalog, and also allow matriculated students to self-enroll in these courses. We don't have an internal 'guest' account creation option at our school so we wanted to use Canvas/Catalog. We are using Microsoft Azure for our school authentication.
We launched the new Discovery page, went through the whole process to let the entire school know the login process was changing, and then realized that we (admins) were all locked out of Catalog. We eventually figured out if we changed the URL from our Custom URL of canvas.wpi.edu/login/saml to our "given" URL of wpi.instructure.com/login/saml then everything worked.
However, then other things started to break. Our users were getting stuck in this loop where if they logged in to the discovery page (canvas.wpi.edu) and then clicked on the "WPI User Login" link (which now links to wpi.instructure.com/login/saml). Then tickets started coming in that the Redirect Tool, and LTIs that utilize our custom URL were now broken. Deep links are also not working, it makes you log in again at the discovery page and then dumps you on your Canvas Dashboard. So generally, the Custom URL and Canvas URL are not retaining login credentials. I've spoken with Canvas Support, our CSM, our IT people- no solutions yet 
Has anyone else gone through this and have any workarounds? Our main requirement was to have both matriculated and non-matriculated users be able to utilize our single Canvas instance, and have Catalog handle the account creation.
Thanks for reading and I appreciate any and all ideas.
-Lindsey
