Subject returning as undefined after update through API

Scenario:

I get a ticket submitted by email.  This triggers a webhook that modifies the subject through the API.  After that, an email notification is sent, but the {{ticket.title}} is returning as undefined.

Here is the part of the payload (pulled before triggering the email notification):

Alert is simple:

I get this:

Any ideas how this happens?  If I trigger the email notification prior to the API update, everything is fine.