Safari Bookmarks do not sync anymore on my iPhone.

The Safari Bookmarks on my iPhone do not sync anymore with Mac Air. I have tried all the recommendations like stop and restart the iCloud sync of Safari both on my iPhone and Mac but it does not work. I have seen more than 64.000 of deleted bookmarks with the recovery data function of iCloud after login with my AppleID credentials, so I am afraid that such very high quantity of deleted Bookmarks generates the issue, but I am not able to definitely delete all the old deleted Bookmarks (they are kept in the account for 30 days), but only few are deleted, therefore I would need some years to delete all :( ... Any further recommendation to re-establish the correct operation of the Bookmarks Sync?

Thanks