See issue 429
  https://github.com/rordenlab/dcm2niix/issues/429
You will want to upgrade to the latest developmental release (or wait for the next stable release) for XA20. The software has also been tested on prototype XA30 data.

For Unix users, compiling the developmental branch would look like this:

git clone --branch development https://github.com/rordenlab/dcm2niix.gi...
cd dcm2niix/console
make
./dcm2niix

Windows users can get a compiled copy from AppVeyor
  https://ci.appveyor.com/project/neurolabusc/dcm2niix/build/artifacts

With Siemens XA, please remember to export enhanced. Never export as mosaics and never choose to anonymize data from the console.