In Contact Person : Check box always select Gray color & itrator lr _entity->get_property_as_string( not showing any value)

In Contact Person having Work Address as assignment block.

When I create new Work Address, it will open new window , there I feel all Contact Person information

There are two field

1. Main Address (Its Check Box)
2. Department (Department name as description text fields)

1)After filling all information when I click back at Work Address assignment block and try to click on save button.

Assignment block showing Main Address fields as always selected and in Gray color (Even user did not select check box or tick mark check box)

2) Second thing Department value is not coming when I select Back button and try to save Contact person information in Assignment block of Work Address.

I debug and found details like below for department.

In debugging

OBJECT_NAME  =    BuilContactPerson

when I click on ATTRIBUTE_REF ->{A:8769*\TYPE=CRMST_CONTACT_PERSON_OBJ_BUIL}

                                    BP_NUMBER

                                    DEPARTMENT = ?

For last nitration its shows value blank

Below is my piece of code

Method GET_ZZDHLDEPARTMENT (ZL_BP_ADDR_CONTACTWORKADD_CN06)

IF iterator IS BOUND.
current = iterator->get_current( ).
ELSE.
current = collection_wrapper->get_current( ).
ENDIF.

lr_entity ?= current.

lr_entity = lr_entity->get_parent( ).

IF lr_entity IS BOUND.
TRY.
lv_abtnr = lr_entity->get_property_as_string( iv_attr_name = 'DEPARTMENT' ).

SELECT SINGLE bez20
INTO value
FROM tb911
WHERE abtnr = lv_abtnr
AND spras = sy-langu.
RETURN.
CATCH cx_crm_cic_parameter_error.
ENDTRY.

…… … … …

End method.