I see. The “Global Page Header” Block Elements is somehow appearing on that specific page even though it’s excluded. I can see though that there’s 3 copies of that page when trying to exclude. Can you try excluding all 3?
This issue of duplicate pages might be because of a third party plugin. Can you try #1 here?: https://docs.generatepress.com/article/debugging-tips/
It would be good to take a backup of your site first before doing this.
Can you also try rebuilding your permalinks? Go to Settings > Permalinks and just hit save.