Why don't I see 1090 ADS-B traffic in ForeFlight when using my Garmin GTX-345?

The software interface provided to us by Garmin does not differentiate between 1090 (ES) and 978 (UAT) ADS-B traffic. ForeFlight, therefore, does not display the source frequency (either 1090 or 978) for this traffic on the map as of version 9.1.