I am using 4.7.13 on two different sites. On one site, when I update the class and refresh my custom report, all of the changes are visible. On the other site when I do the same thing, the changes are not visible. Even stranger, when I delete the class (i.e., the PHP file), the report is still visible in its old form. I have tried 'flush all cache' and searching for any other cached versions without success. Since this works on one site but not the other I suspect there is some configuration setting that I am missing somewhere.