LookupRecord with DatabaseLookupService

[#1]

Hi, collegues!
We have stucked at this issue.
Our incoming JSON
{

GUID: 123432,

UserName: "John Silver",

Department: "Headquarters"

}

And lookup table in the Oracle database consits of two columns: id, desc.

What we want to achive is get the id from that table by provided description from json (for instance Department field).

After LookupRecord processor with following key settings:

Result RecordPath => /Department

Record Result Contents => Insert Record Fields

Record Update Strategy => Use Property

User-definet propery:
key => /Department

We get JSON as follow:

{

GUID: 123432,

UserName: "John Silver",

Department: "MapRecord[{ID = 7107070}]"

}
What we are doing wrong or probably not in correct way?
Really appreciate for any clue)