Hi! Unfortunately, I don’t have an answer or solution, but I think I’ve been having a similar issue on my iPhone and posted about it recently:
https://forum.inaturalist.org/t/empty-projects-list-in-ios-app-and-error-422/21648/3
Does it seem similar to that?
I hope the problem is resolved soon or we can figure out a solution. Following your thread to see if there are any answers. 