Missing main_motif text in tab on artworkpage

[DPhuongHda]

Describe the bug
While the tab main_motif + images exists, the tab box has no text:

To Reproduce
Steps to reproduce the behavior:

1. Go to https://openartbrowser.org/de/artwork/Q3751961
2. Scroll down to related artworks carousels
3. See missing text

Screenshots

This error probably has something to do with i18n.