(2nd try sending this reply...)
Thanks Asyn,
I implemented your suggestion and my weekly scans resumed 2 weeks later. But I don't know if your solution was decisive, because the conditions that determine when and whether the scan launches seem to change without notice. Now the weekly scan launches regularly, but long before the specified time (by the way, it bothers me during my work). Some time ago, it used to launch a little later whenever the computer was off at the precise time specified for the scan. Later, the scan was simply skipped if the computer was off at that time. So it's difficult to understand what is going on and to manage this functionality.