There is a limitation today with Forge causing embedded Confluence pages, that can be configured in Forge apps using https://atlaskit.atlassian.com/packages/confluence/embedded-confluence-public, not to function.

This is due the following factors:

• Forge apps not allowing pop-ups (due to Forge security requirements)
• Browsers (like chrome and firefox) have disabled third-party cookies by default

Due to these limitations, embedded Confluence pages do not work in Forge apps. Users are asked to allow & login to Confluence, but the operation is blocked and the embedded pages do not render.