Keyboard focus order is incorrect in the chat popup screen.

Test Environment:
OS: Windows 11 25H2 (OS Build 26200.6584)

Browser: Edge (Version150.0.4078.42)

URL: https://www.intercom.com/helpdesk

User Impact:

Keyboard-only users will face difficulty navigating the chat popup screen, leading to confusion and inefficiency. This can prevent them from accessing critical controls, impacting usability and accessibility compliance.

Repro Steps:

1. Open the URL:  https://www.intercom.com/help/en/articles/9639255-getting-started-with-intercom in edge browser in windows.
2. Landing page will open.
3. Press tab key to navigate to the chat button and activate it.
4. Verify whether keyboard focus order is incorrect in the chat popup screen in windows or not.

Actual Result:

Keyboard focus order is incorrect in the chat popup screen in windows. After activating the chat control focus is moving to edit field instead of first interactive element i.e. back control.

Refer Attachment:

1. Keyboard focus order is incorrect in the chat popup screen in windows.png
2. Keyboard focus order is incorrect in the chat popup screen in windows.mp4

Expected Result:
Keyboard focus order should be correct in the chat popup screen in windows. 

After activating the chat control focus should move to first interactive control i.e. Back control and keyboard focus shouldn't move outside of the chat popup without closing it.