Universal Login in Office Add-in (Excel), exchange not happening

Hello there

I trying to use Auth0 in a office add-in (React SPA), specifically Excel.
I am using the popup to login instead of the redirect because the redirect doesn’t load in the iframe.

(The error for the iframe is "Refused to frame because an ancestor violates the following Content Security Policy directive: “frame-ancestors ‘none’” ").

The issue I’m having is once I login successfully, the pop just goes white and gets stuck on the login/callback.

I’ve checked the logs, it says a successful log but it doesn’t say anything about an exchange (success or failure).

I’ve tested the pop up on a different application (react web app) and it works perfectly fine.

The login we are using is the Universal Login (the new one, not the classic)

I’m interested in any and all approaches for using the Universal Login in this context.

Thanks