Restore From Database
When you restore a database “FROM Database” in SSMS you are restoring from the last backup set of the database not from the live database itself. This might not appear apparent in the GUI.
Notice when you choose from the database dropdown list you are seeing backup sets.
If you use the script button in the gui you will see “FROM DISK” -
Another clue will be that any database that has not been backed up will not appear in the drop down list.
