Unable to redirect to `mailto:`

I’m trying to create a contact middleman injecting a localized subject to an email.

const uri = `mailto:${handle}?subject=${text}`
return Response.redirect(uri, 302)

When running locally it works as intended but after publishing the script to CF I get exceptions when calling the script.

"exceptions": [
      "name": "TypeError",
      "message": "Unable to parse URL: mailto:[email protected]?subject=subject text",
      "timestamp": 1669423847079

Full log can be made available to CF staff upon request.