The difference is due to the timing of the investment transactions. We do not know the actual start and end dates of the reporting period; however it seems like the bulk on investment was made near the end. The start value is adjusted by the weighted average of investment amount and time between the start date and investment dates. In this case, under the money weighted return, the principle value was lower for the majority of the reporting period (until the capital injection) resulting in a higher return calculation for the entire period.