Common Data Service - List Records - expand

Hello fellow Flow-ers,

I'm having a little trouble with the Common Data Service - List Records step when I try to use the expand clause to include data from a related entity. I can't see anything that says this shouldn't work, but perhaps I have missed something. I am aware that the OData API is case-sensitive. I have two entities related in a 1-to-many way. If I make the Support Request Outcomes the main entity the flow will generate results.

However, there may be some Support Requests without Support Request Outcomes, so I want that to be the main entity in the step and expand to pick up the related Support Request Outcome records. If I try this my flow step fails.

The error message is:

Could not find a property named 'hs_supportrequest' on type 'Microsoft.Dynamics.CRM.hs_supportrequest'.

The relationship is called hs_supportrequest on the Support Request entity while it is called hs_SupportRequest on the Support Request Outcome entity.

What am I doing wrong?

Any help gratefully received!