Notion OAuth using launchWebAuthFlow “Uncaught TypeError: Cannot read properties of null (reading 'postMessage’)"

Question

I am trying to create a Chrome extension that uses the current Notion OAuth authentication.

When I pass the following authentication URL to launchWebAuthFlow, it will open with Identity api scope approval ui and ask me to login to notion.

https://api.notion.com/v1/oauth/authorize?owner=user&client_id={clientId}&redirect_uri={redirectUrl}&response_type=code

When logging in to notion with an email address or Apple ID, the subsequent flow also proceeds in the Identity api scope approval ui and is successful.

However, if you try to log in to Notion using Google, a new Chrome tab will open and the flow will proceed in Chrome, eventually resulting in a blank page with the following URL and failure.

https://www.notion.so/googlepopupcallback

The following error message was displayed in the console Uncaught TypeError: Cannot read properties of null (reading 'postMessage')

I have done a lot of research, but I am at a loss as to the cause of the problem and how to fix it. If you have any knowledge, please advise me if you can.