Traditional Projects with observation fields not working

Platform (Android):
App version number (unknown: 3 people reporting the error on different devices):

Adding a traditional project on the Android with obligatory observation fields, does not allow the fields to be added. The project is added, but the fields are not displayed or provided to select from, and subsequently the project fails to load into the observation.
In the reported cases we are dealing with:
https://www.inaturalist.org/projects/habitats-s-afr
with the obligatory field [Habitat (s Afr)]: https://www.inaturalist.org/observation_fields/7498

The iPhone version works fine (as does the web Upload version, provided that you add the observation field):

Closing to focus discussion on existing bug report.