Use Signature Flag being ignored when using Lightning Email Template

[AtlantisFury]

I have an email action configured in Flow to send an email using a Lightning Email Template. Since I am using a template, I understand from the documentation that all custom content fields cannot be used due to a limitation in Apex. For that reason, I have all the custom content options set to "Don't include", however, when the email is fired by flow, the running user's personal signature is appended to the bottom of the email, after the contents of the template. The signature should be excluded since that option is set to "Don't Include" and I am using a lightning template instead.