Workflow Not Working Consistently

Workflow Not Working Consistently

I have a workflow and alert set up for when someone applies for a position. It is set to send an automatic email to candidates who apply for positions.

Workflow is set correctly and active. I currently have 40% of candidates receiving the emails but 60% are not.
I can also see this in Zoho Recruit under applicants profiles, no record of an email sent but other applicants do have records of the same email sent.