GPO on task scheduler shutdown does not reapply

HI, i have created a gpo to create a task scheduler to shutdown the PC at 9:00 pm
i applied and it works fine, now after some weeks i didn't find any more the task scheduler on PC. i checked the gpo again and then i find the gpo common properties options that i have checked "Remove this item when it is no longer applied"
i remove this check and run gpo update several time but the scheduler wont appear on client PC.
Now i am asking why is this error happening and how can i solve this problem in a fast way
Thanks !