The workflow itself is obscured so I cannot tell if this is causing your problem, but I do see that the notification has the box 'Don't send if obsolete' selected. This is selected by default for notifications on Eligible. If another step becomes eligible after this step but before the notification service processes this step, the notification will be suppressed. This happens easily when parallel paths in the workflow are executing concurrently. It will also occur if the step is exited before the notification is generated.
You can run the Notification History Report to see what notifications have been generated for the request. If the notification was generated properly, you will need to check out your email infrastructure to see what it did with it.
you can make use of the KNTA_NOTIF_REFERENCES_V view, which displays all notifications configured for workflows. Based on the DDL of this view, you can create an update statement for the KNTA_NOTIFICATIONS table to set ENABLED_FLAG = 'N'.
let me know if this helps.
! don't forget to commit the changes :)
--remember to kudos people who helped solve your problem