These are my permission levels on a custom object:
Profile: Public Read/Write OWD: Modify All
I was expecting to see a 'Sharing' button for all the records but I am not able to see this button on any records including the ones that are owned by this user but the 'Sharing' button appears with this combination:
Profile: Public Read-only OWD: Modify All
Doesn't 'Modify All' override all the sharing settings and give all permissions to all the records to the user?