$_ENV used in mailer not resolving properly

Wappler Version : 3.9.4
Operating System : mac
Server Model: node
Database Type:
Hosting Type: custom

Expected behavior

Using an $_ENV in the password of a mailer should resolve properly

Actual behavior

I receive an error indicating the authentication is invalid.

How to reproduce

Setup a mailer action (eg. Sendgrid) and use an environment variable for the password:

Screen Shot 2021-04-08 at 8.14.36 AM1170×1026 45.7 KB

Troubleshooting performed:
I setup an api action to output the value of $_ENV.SENDGRID_KEY

Screen Shot 2021-04-08 at 8.15.10 AM1036×1172 58.3 KB

And executed the api:

If I put the key directly into the password field of the mailer, rather than through a variable, the email is sent fine, which indicates they api key is valid.