Yes please investigate. As I have been able to now recreate all the missing German product categories on live site and it is generally working better. Some of the missing translations like the info page has now worked as well. Other pages are still having some issues with some links ref our other ticket.
To understand why some users can't translate I'd need their credentials, since it's working with user. If you prefer, you can change them first in the dev site before providing them.
I have set the same password. The other user account you can see from users section and this was the one I was using before. I have not retried it since changing the password. I will leave the testing for you.