Clicking "return to table" in a detail view with unsaved changes gives an error

When editing any entity (testes with a locality and a time unit), then leaving via the "return to table" button, the following error appears:

<img width="757" height="428" alt="Image" src="https://github.com/user-attachments/assets/666c6aac-62d3-45a4-9aa7-d6ebb9228d11" />