This issue effects Chromevox Next. I utilize LastPass for password management, and I need the ability to be able to right-click when focused on an edit box in order to bring up options for password management. However, performing the command Shift+Search+Volume Up most of the time causes the menu to be announced briefly, however the menu then exits. Please find repro steps below:
Mode: force_next
Version: 52.0.2712.0
Reproduction Steps: 
1. Enable Chromevox Next
2. Navigate to any web page with an edit box and place the focus of the cursor in that edit box.
3. Press shift+search+vol-up.
Expected Result: Chromevox would say "menu" to alert a user that the context menu has appeared. A user would then be able to traverse this menu with the up/down arrow keys.
Actual results: Chromevox announces the menu and promptly exits the menu. Upon the second or more presses (the frequency is not consistent) the context menu stays on screen with Chromevox able to access the menu options with a press of the up/down arrows.