This may not assist you either, but I have a similar problem. I have a Wi Fi only Ipad and have downloaded Air Nav Pro and purchased (on recommendation) a Garmin GLO.
I cannot receive a signal on the ipad when in the aircraft and even when at home on wi fi, when I
choose 'nearest' it selects an unknown location 3000 miles away ??
Very disappointed after downloading all the charts etc. My friend has a 3G Ipad which works fine with Nav Pro.
Where are we going wrong. Ive reverted back to my 496.