RE: Field with Data Type Autonumber Doesn't Increment
                     
                    
                      
                        Hello,
I think it kind of makes more sense in the Unified Interface, because Auto Number fields generate an incremented value only if the field is left empty. You can perfectly choose to enforce a specific value at creation time for the record, if you don't want the system to generate one for you.
So if the field is mandatory, it expects that you provide a value upon creation.
I think your workaround is the right approach, and if you want to ensure that users don't input random values, make the field read-only.
Henry