In the trend below we can see that Totalise resets to 0 on 30th June because it has the interval set to 90d.
Set the data in the KPI to 30-Jun-2021 23:59:59. The TOTALISE function shows 1 because it reset after 29th June because there are actually 91days in the quarter (April + May + June), whereas the TOTALISE2 function gets the number correct at 91.