WoWInterface - dungeonAreaMapID returned from EJ

Lua Code:

name, description, bgImage, buttonImage, loreImage, dungeonAreaMapID, link = EJ_GetInstanceInfo([instanceID])

I need the dungeonAreaMapID for Atlas, but it looks like GetInstanceInfo() somehow will not return a valid value for this and I will get "0" as the returned value.
It's interesting that Blizzard use below codes in the Blizzard_EncounterJournal:

Lua Code:

local _, _, _, _, _, _, dungeonAreaMapID = EJ_GetInstanceInfo();
    if dungeonAreaMapID and dungeonAreaMapID > 0 then
        WorldMapFrame.fromJournal = true;
        ShowUIPanel(WorldMapFrame);
        SetMapByID(dungeonAreaMapID);                                           
    end

So that means they know somehow the value will be 0?

I need to figure out a firmed way that I will always get the expected dungeonAreaMapID value.