Hi,
I’ve just tested it on my server, and it seems to be working fine. One note though – if you are referring to our “Relate Manually” settings, you will need to set the related categories for both translations of your category, i.e. in “Products > Categories > Original category (DE)” and in “Products > Categories > Translated category (EN)”.
If that doesn’t help – would it be possible to share access to your site, so I could log in and check what’s going on (my email is [email protected])? Please let me know if sharing an account is not an option, and I will continue solving it remotely.