Create a microflow that accepts Shift_Report entity as a parameter. In the microflow, retrieve the list of Shift_Report_Entry via association with the Shift_Report entity (retrieving via association ensures you get any uncommitted changes to those objects). Commit Shift_Report and the list of Shift_Report_Entry objects. Call this microflow instead of the standard Save button.
Alternatively, if your Shift_Report_Entry objects are in a List View, you can Save Changes on each field as they are changed. Open the properties of the widget used (text box, reference selector, etc.) and select Save Changes as the on change action.