Problem: You are experiencing issues with editing a page on your multisite setup, where attempting to edit the page forces a login screen, and subsequent login redirects you back to a different domain. Solution: We recommend checking the 'Automatically log in and log out users across all domains' option in your WPML settings. This setting can be found under WPML > Languages in your WordPress admin area. Enabling this option should resolve the issue of being redirected after logging in. If you need to log in again when trying to edit the page, this should be expected, but it should allow you to proceed with editing without further redirections.
Please note that this solution might be outdated or not applicable to your specific case. We highly recommend checking the related known issues, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the issue persists, please open a new support ticket.