johngalt

From that picture we cannot tell the parameters that are being passed for the Defender scan to run. Also, we cannot tell if the task itself (not the scan, the *task* as set up in Task Scheduler) is set to wait upon the completion of the Defender scan or to start the scan and then once the scan starts acknowledge that the scan has *completed* before marking the task successful.

Finally, it could be that, if you have not installed any new programs, everything that it has been scanning for the last so many times is now cached, and since nothing has changed, the scan ends pretty quickly.