Steps to reproduce:

1. for example, open the NVDA add-ons manager, and press on install add-on button.
2. when pressed, the open dialog appears to chose the add-on.
3. press shift+tab twice to go to the file list.
4. find the desired file you need

Actual behavior:

file and folder names are pronounced twice, for example ad-on updater.nvda-addon, or the folder name add-ons add-ons

Expected behavior:

Folder and file names should be spoken once, as in NVDA 2019.2.1

System configuration

NVDA installed/portable/running from source:

installed and portable

NVDA version:

latest NVDA beta 2019.3 beta 1 and the last snap from the alpha branch

Windows version:

10.0.18363

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

n/a

Other information about your system:

DualCore Intel Core i7-7500U, 3500 MHz (35 x 100),
8GB DDR 4 (2133)
tested also on my lenovo ideapad 320 15isk intel i3 6006U

Other questions

Does the issue still occur after restarting your PC?

yes

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

2019.2.1, this version pronounces file and folder names in the windows explorer open dialog file list once.