The Safari browser on your Mac en other Apple devices can sometime go out of sync. Bookmarks, open tabs and history will not synchronized with other Apple devices. It’s possible to force synchronize the bookmarks and other iCloud content manually, this can be done with Safari Debug menu. You must activate this menu with the following Terminal command.
defaults write com.apple.Safari IncludeInternalDebugMenu 1
Launch Safari, click on the new “Debug” menu and choose the option ‘Sync iCloud History’ to forcesync Safari history and bookmarks on your Apple devices.