Null results when calling scalar functions on unwound virtual nodes and relationships

[egglessness]

I'm trying to query Neo4j to get the graph schema in the D3.js JSON format ({"nodes": [], "edges": []}) but I'm encountering a strange behavior when I call scalar functions like labels(), startNode() or endNode() on unwound nodes and relationships.

I noticed this behavior when I run the following query:

CALL db.schema.visualization() YIELD nodes, relationships
UNWIND nodes AS n
UNWIND relationships AS r
RETURN {
    nodes: COLLECT(DISTINCT({key: elementId(n), attributes: {type: labels(n)}})),
    edges: COLLECT(DISTINCT({source: elementId(startNode(r)), target: elementId(endNode(r)), attributes: {type: type(r)}}))
}

If I run it, I get an unexpected graph: all the edges go from/to the same node, and all the nodes have no label

Returning the unwound nodes and relationships without any further processing works fine, so I suspect there is some issue on how scalar functions handle virtual nodes and relationships returned by db.schema.visualization().
Using apoc.meta.graph() leads to the same results.

Environment

• Neo4j version: 5.14.0
• Operating system: Debian 11.8 (Docker)
• API/Driver: Neo4j Browser

Steps to reproduce

1. Unwind nodes and get their labels:

CALL apoc.meta.graph() YIELD nodes, relationships
UNWIND nodes as n
RETURN labels(n)

2. Unwind relationships and get starting and ending nodes:

CALL apoc.meta.graph() YIELD nodes, relationships
UNWIND relationships as r
RETURN elementId(startNode(r)), elementId(endNode(r))

Expected behavior

1. Should return a list of lists of node labels
2. Should return the IDs of the virtual nodes

Actual behavior

1. Returns a list of empty lists
2. Returns always the same start/end node for all the relationships