I have uploaded a number of private models using my laptop. When I try to open them in the iOS Sketchfab app on my iPhone (logged in with the same credentials of course) I just get a message that the model is private. There is no option to enter the password, I can only return to the previous page.
This only happens within the app. Using Safari the model loads as it should.
This is not an isolated incident but happens to all password protected models.