HubSpot Calling Extension SDK is broken in Safari

[smartfba]

Checklist

• [x] I have read the FAQs.
• [x] I have checked the issue tracker for duplicate issues.

Description

HubSpot shows the error There was an issue connecting with <<Extension Name Omitted>>. in the calling modal.

Web Developer Console contains error:

Unable to post message to <<iFrame URL Omitted>>. Recipient has origin https://app.hubspot.com.

Expected behavior

The Calling Extension frame becomes visible, and the widget receives messages/events from HubSpot.

To Reproduce

1. Install a Calling SDK Extension Demo per the instructions.
2. Click the Call button on a Contact.
3. Look at the Developer Console.

Screenshots/source code

Device information

Device: MacBook Pro OS: macOS 13.4 Browser: Safari Browser Version: 16

Additional context

Chrome does not have this issue.

[smartfba]

It ended up being a Content Security Policy (CSP) issue that was only present on Safari. Thanks anyway.