http://adsbx.org/sync/feeder.html?4B&Scharnhausen-01 It's here ... odd you don't have any peers ... Are you sure your latitude and longitude is correct?
The Scharnhausen-01 entry is from my prevoius installation bevore I updated to the new Radarcape firmware. But the receiver and antenna location does not have changed from before. The Radarcape GPS report the location well: https://google.com/maps/?q=48.71099,9.26532 At the Radarcape Feeder Setting is only an Enable command (see attachement). Walter
Well then don't use the internal ADS-B feed, i would expect they only implemented sending the beast data, not MLAT.
My guess is they didn't implement MLAT client. Only beast feed - which is fine. MLAT is not so important now that ADS-B is widespread. If you are interested in Military that isn't ADS-B equipped. You'll need ADSBX unfiltered MLAT.