NVDA not reading PowerPoint Outline view (just reads linefeed)

[SMTestGH]

Steps to reproduce:

1. Enable NVDA 2021.1
2. Open PowerPoint
3. Select blank presentation
4. Type text into the Title text box on slide 1
5. Navigate to View > Outline view Alt>W>PO
6. Press F6 until focus lands in Outline view
7. Arrow up/down to read text

Actual behavior:

NVDA doesn't read the text in the Outline view. Only reads "linefeed" and "blank"

Expected behavior:

NVDA is able to read all text in the Outline view

System configuration

NVDA installed/portable/running from source:

Portable

NVDA version:

2021.1

Windows version:

21H1 version 19043

Name and version of other software in use when reproducing the issue:

PowerPoint for Office 365 - any build from 2019 and up

Other information about your system:

Issue does not occur using Narrator - text read correctly. Likely presented via UIA that NVDA is not capturing.

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

Repros in old versions too (2020)

If add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Yes