Headings tool not detecting any headings on pages built on Cascade

[mairaw]

Describe the bug

To Reproduce
Steps to reproduce the behavior:

1. Go to https://azure.microsoft.com/en-us/products/ai-foundry/, https://www.microsoft.com/en-us/microsoft-365 or https://www.microsoft.com/en-us
2. In Accessibility Insights for Web, go to "Ad hoc tools > Headings" and toggle it on
3. Observe that nothing happens

CodePen repro example

Expected behavior

Headings present on the page would be highlighted

Screenshots

Context (please complete the following information)

• OS Name & Version: Windows 11
• AI-Web Version & Environment: Version 2.49.0
• Browser Version: Microsoft Edge - Version 152.0.4191.66 (Official build) (64-bit)
• Target Page: https://azure.microsoft.com/en-us/products/ai-foundry/, https://www.microsoft.com/en-us/microsoft-365 or https://www.microsoft.com/en-us

Are you willing to submit a PR?

Only if straightforward. Not familiar with the implementation of this tool.

Did you search for similar existing issues?

Yes

Additional context