POST to mysql error: user_id_on_create always 3

For some reason when I create a new record for my database table I am met with the following error:

      "code": "23000",
     "message": "SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '3' for key 'ID' (SQL: insert into `bitnami_df`.`mobileusers` (`Email`, `ID`, `Pass`, `NiftyID`, `CRMid`, `BooksID`, `Confirmed`) values (, 3, 5456, 444, 444, 566, 1))",

Has anyone had this issue or know a resolution?

Can you please post the schema of the table mobileusers using _schema/mobileusers endpoint? Are there any constraints on the ID field?