Version: 66.0.3329.0
Reproduction Steps: 
1. Enable CVox and navigate to inbox.google.com
2. Press j to jump to a bundle and press enter to open it.
3. Press j to put focus to the first message.
Expected: The content of the first message subject, sender, and any other information would be uttered by Chromevox, as does happen with other screen readers.
Actual: Chromevox utters close, close, close, and looses responsiveness to any attempt to get it to behave. The only way I have found to reset this behavior is to turn off Chromevox and turn it back on by pressing CTRL+ALt+Z