Unable to fetch records using unidirectional @OneToMany relationaship JPA

I'm unable to fetch records using a unidirectional @OneToMany relationship in JPA. Any idea if anything is missing? Records are getting persisted though; only retrieving records is having problems.

class Employee{

    int empId;
    ...
    @OneToMany(cascade = ALL, mappedBy = "deptId",fetch = FetchType.EAGER)
    List<Department> departments=new ArrayList<>();

    //getters and setters

}

class Department{

    String code;
    ....
    int deptId;

    //getters and setters

}

empRepository.findById(empId).getDepartments(); // is not returning rows even if records are available.