Troubleshooting Task Scheduler Help Needed

Running 42.1 with KDE desktop my Task Scheduler, set to run every night while I sleep, appears to have stopped working. Only change I have made is that I now log out at the end of each day.
The Task Scheduler runs correctly if I press “Run Now” button and the schedule is set

15 2 * * *

which I think should be 02:15 hr every day.

PATH variable is set to:-

/home/alastair/perl5/bin:/home/alastair/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games:/usr/lib/mit/bin

Where have I gone wrong please?

If set as a user it only runs when that user is logged in. It needs to be set up as root to run when no user is logged