Describe the bug
If Node B is a child of Node A in a file that does not have an ID property, then a link from Node B to Node A will not be displayed.

What browser were you using?
Firefox

Additional context
I believe that the cause is this chunk of code in index.tsx:

if (!fileNode) {
  return []
}

This suggests that the behavior might be intentional, although I'm not sure what the rationale is.