I have the same problem.
Did you figure it out?
Can’t find any errors.
I am not realy happy with the documentation.

My config looks like this:

{
                       module: 'MMM-PublicTransportDB',
                       position: 'top_right',
                       config: {
                               name: "MMM-PublicTransportDB",
                               hidden: false,
                               stationId: 8001005,
                               ignoredStations: [],              
                               excludedTransportationTypes: ' ',   
                               direction: null,                    
                               marqueeLongDirections: true,
                               delay: 12,                         
                               interval: 120000,              
                               departureMinutes: 300,              
                               showColoredLineSymbols: true,       
                               useColorForRealtimeInfo: true,     
                               showTableHeaders: true,
                               showTableHeadersAsSymbols: true,  
                               maxUnreachableDepartures: 3,        
                               maxReachableDepartures: 7,        
                               fadeUnreachableDepartures: true,
                               fadeReachableDepartures: true,
                               fadePointForReachableDepartures: 0.25
                       }