OData Query for Azure Data Factory SPO List Connector Doesn't Return Expected Results

I am trying to run an OData query via a SharePoint Online List connector in Azure Data Factory, here is my query:

$select=Id, ProjectId, Project/Id, Project/Title&$expand=Project

"Project" is a lookup column within the list.
When I preview the data in ADF I can see ProjectId and Id, but I cannot see Project/Id or Project/Title.

I am undoubtedly doing something wrong; I think my query is correct, so could this be a limitation of the connector?

Could this be a permissions issue? I am connecting via a service principle key.

Is the $expand syntax applicable in this context? The query parses ok and returns results, it just doesn’t return all the results I expect.

I have been looking at multiple MS docs to try and find the answer, and have been questioning the syntax for days. This is the first time I have used this connector, so am unsure what the problem could be.

I have three main questions:

1. Is this the best method for this type of query? Should I be using a method such as the following
2. Is the query correct, and if so why does it not return the results I would expect?
3. What is the best way to overcome this problem?

Thanks in advance for any help/advice that can be offered on this.