This GET request https://data.developer.nhs.uk/ccri-fhir/STU3/MedicationStatement?patient=1010&_format=json will return the payload of the MedicationStatement where the patient logical id is 1010. However, this GET request https://data.developer.nhs.uk/ccri-fhir/STU3/Patient?_id=1010&_format=json&_revinclude=MedicationStatement:patient returns the patient with the logical id of 1010 but the MedicationStatement payload does not return.
This GET request https://data.developer.nhs.uk/ccri-fhir/STU3/MedicationStatement?patient=1010&_format=json will return the payload of the MedicationStatement where the patient logical id is 1010. However, this GET request https://data.developer.nhs.uk/ccri-fhir/STU3/Patient?_id=1010&_format=json&_revinclude=MedicationStatement:patient returns the patient with the logical id of 1010 but the MedicationStatement payload does not return.