Altasl - one of my models shows correct (about 1875 meters), the other shows 0. (Kakute F7 might be at fault)

I have a Pixhawk and a Kakute F7, both running aurducopter.

On the Pixhawk, the altasl field shows my actual altitude above seal level…about 1875 meters.

On the Kakute F7, altasl shows zero (fluctuating around a bit). Also…I run the Yaapu script on my Taranis X9D…and it shows 1900 meters for GALT.

  1. Why the differences in the altasl field?
  2. Why, even when altasl is showing zero, does Yaapu show 1900m? Maybe Yaapu is still getting the raw data?

And what’s maybe a different/separate problem…Yaapu (with the Kakute) is only showing the GALT to the nearest 100 meters.

So as I climb, at some point the GALT goes from 1900 meters to 2000 meters, and then back to 1900 meters as I descend (but the baro is showing the altitude above ground).

I’ve two separate GPS models and all the altitudes behaved the same way.