Hi @evankoh,
While looking at the Debug feature of the Portfolio Xirr Computation Details, I noticed that the tool computed dividend as cash inflow at XD date instead of Pay Date.
Thank you for reporting. Let me check on that.
Under Portfolio ( StocksCafe), user is able to select multiple portfolio for the report tab to check the result table which is very useful to check what is different strategy implemented on the impact of the portfolio. In the debug mode, user are not able to select multiple portfolio to debug.
Need to implement. Cannot remember how easy or hard to do so.
Also, debug mode is meant to understand the computation and to point out issues like you just did 
Done. Changed to based on PayDate.