When I try to adjust the clock, Zulu Time is wildly off and cannot be adjusted at all. Local Time lets me adjust the hour, but the minutes jump in 30 min increments, thus cannot set correct time. I have an in-panel GPS (EKP-4), but I think it is connected only to the transponder, for ADS-B out. I have a Bad ElF external GPS I use for Foreflight, but it requires Bluetooth to connect with other devices Do I have to give up on the EMS clock functions?