Question mark appearing in email quick action

I am using a basic template to send an email from a Contact record, and after I send the email it inserts an errant question mark into the subject line of the email. This is a little bit embarrassing. How do I eliminate the question mark? Here's my subject line:

Welcome {{{Recipient.Name}}} - Onboarding

In the template I've cleared and retyped this text from scratch. I've also cleared and pasted into a text editor to make sure there's no odd formatting, then pasted it back. No luck. In the first comment I am uploading a screenshot of what the test email looks like in my own inbox. Appreciate the help.