Aggregate (Reflexive Join) in MongoDB - mongodb

Question

I have the following data in collection "sampleorgchart":
Eventually we want to use the "Relationship" field in a match/filter statement, but first I just want to get some demo query to work with the hierarchy.
I am trying the following:
db.sampleorgchart2.aggregate([
{
$graphLookup: {
from: "sampleorgchart2",
startWith: "$To",
connectFromField: "To",
connectToField: "From",
as: "myList",
maxDepth: 2,
depthField: "depth"
}
}
])
It runs, but return 0 items in each of the "myList" fields:
// 1
{
"_id": ObjectId("6180023c68600000010000f5"),
"From": "John Doe",
"Relationship": "is CEO of ",
"To ": "Sample Company",
"myList": [ ]
}
Is something wrong with my query? I would like to see the connected rows in "myList".
For further practice, I copied the employee data from this page, and got that query working.
https://docs.mongodb.com/manual/reference/operator/aggregation/graphLookup/#examples
So by changing the collection name and the field names, I don't understand why it won't work with my sampleorgchart2 collection. I got the query that page working, then reversed it to go down the hierarchy instead of up the hierarchy:
db.simpleorgchart.aggregate([
{
$graphLookup: {
from: "simpleorgchart",
startWith: "$reportsTo",
connectFromField: "name",
connectToField: "reportsTo",
as: "myReportingHierarchy",
maxDepth: 2,
depthField: "depth"
}
}
])
Sample results:
// 1
{
"_id": "1",
"name": "Dev",
"reportsTo": null,
"myReportingHierarchy": [
{
"_id": "1",
"name": "Dev",
"reportsTo": null,
"depth": NumberLong("0")
},
{
"_id": "2",
"name": "Eliot",
"reportsTo": "Dev",
"depth": NumberLong("1")
},
{
"_id": "3",
"name": "Ron",
"reportsTo": "Eliot",
"depth": NumberLong("2")
},
{
"_id": "4",
"name": "Andrew",
"reportsTo": "Eliot",
"depth": NumberLong("2")
}
]
}