Sometimes tasker toggle does not trigger the corresponding task, and gets stuck at the busy state.
There is an issue in android where if an application is installed 'before' the dependent application (i.e. Tasker) android does not update the permissions properly. And so the Power Toggles does not automatically get the permission to execute the Tasker tasks, if it was installed before Tasker.
The simple solution is to uninstall Power Toggles and install in again.