I spent some time trying to track down the cause of this problem, and discovered that the Admin Panel ‘distribution’ (node_modules/@strapi/admin/dist) contains chunks under the name of ‘AuthenticatedApp-xxx’ containing an older version number for Strapi.
I would guess that the build & release process for Strapi is broken, as the package.json in the Admin Panel module shows the correct version … It’s as if the module didn’t get rebuilt before it was released. I’m going to raise an issue for the Strapi developers to investigate.
Meanwhile, if you edit the two ‘AuthenticatedApp-xxx’ files (.js and .mjs) and change the ‘const version’ value to match your current version of Strapi, then rebuild the admin panel, the notification will go away. It’s a bit of a fudge, because you won’t be using the ‘correct’ admin panel code.