Ensure/double-check the Connection/Bot has access to the database page of interest (via the “Connections” menu on the 3 dots at the top right corner in Notion)
In the input URL in n8n, remove everything after the “?” (question mark)
In n8n, Refresh the properties section
Try inputting the database page by ID instead of by URL. The ID is what you see between the first / and the ? in the URL (1d43…577)