Populating Item Details Title field with @ does not work

See the screenshot. I am trying to have the Item Details “Title” field populated by a database field. I can select the database field, but when displaying the Item Details page, the value is not shown.

I have tried this with the Softr database and with a Notion database as a source.

When I select the Softr database as a source, I can only get the field populated if I add the Title field in a section on the same page.

What am I missing?