You have configured a scheme that hibernates a PC during the day because of inactivity, that also shuts down the PC after 6pm. But the machine is not shutdown after 6pm because the machine is already hibernated.
Because the machine is already asleep it is no longer processing power schemes and as such is incapable changing it’s state from hibernating (or suspended) to shutdown, or any other state. This would be normal behaviour and completely unavoidable unless the machine were first woken up.
The only way to guarantee a machine is shutdown, that may already have the potential to be asleep when the event should occur – is to; include a wake event a few minutes before the shutdown event should occur. This will guarantee the machine is able to process the power scheme and implement the correct sleep state.