Assume there is one page in the space.
If this page was created and edited some times in the past, the current changes are 0 in the report, if the changes are out of the date range. This is correct.
If this page becomes edited now and the report is visited, the change is still 0. This is wrong
If the page is edited a second time and I go to the report it starting by one with the change. This is semi correct
If a new page is created within my report configuration, the count is correct.
It only is wrong, if the creation date is before the report start date.
There is a "minus one" of one for the creation of the page, but if the page was created in the past such minus one" is wrong.