NVDA not reading the equation fields in microsoft word

[Aarushb]

Steps to reproduce:

1. Open a blank word document. (word 2013 or higher)
2. Press 'ault+equals' to open up the equation field.
3. Type something like '\alpha ' or '\sqrt 2' and then press enter. Clearly, it doesn't read them the way it should.
4. Now go to NVDA menu>settings>advanced>'Use UI Automation to access Microsoft Word document controls when available check box checked Alt+w'
5. After doing this, try the steps above and NVDA will now read all the equations and symbols in the field.

Actual behavior:

'2'

Expected behavior:

'link Equation page 6 baseline square root of 2'

System configuration

NVDA installed/portable/running from source:

Installed

NVDA version:

2021.2

Windows version:

10

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

MS word(office 365)

Other information about your system:

Core I7 third generation, 8 GB ram.

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.

All versions starting from 2019.1 , similar behavior.

If NVDA 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
##extra information
NVDA seems to perform better overall with the above setting enabled, and is a lot more responsive. With it off, there is a noticeable delay when interacting with word to this day, but there are also some nasty bugs when having it on such as NVDA not reading auto-numberring, table sells, etc. It would be nice if everything could be integrated into the sr by default itself without having the advance features on.
bug_sample.docx
This is a docx file with a sample equation, as well as the equation's content in plaintext.

[lukaszgo1]

This is essentially a duplicate of #4631 and as such should be closed. Having said that:

[...] but there are also some nasty bugs when having it on such as NVDA not reading auto-numberring, table sells, etc.

The intent is to have UIA enabled in word by default in 2021.3 so all these issues should be reported, preferably after testing with the last Alpha.

[seanbudd]

Closing this as it's a duplicate of #4631 - please do test this with alpha, or 2021.3 beta when it is released.