Latest version of software at the time of filing this bug. Chrome 61, Jaws 18 and NVDA 2017.2.
1. Navigate to the following URL:
data:text/html,<details><summary>Summary</summary>more info here</details>
2. With Jaws or NVDA running, use the cursors to find the "Summary" button and press it by pressing enter or space.
2. Notice that it doesn't expand, i.e. the "More info here" message doesn't appear in the virtual buffer and the visually the widget stays the same.
3. Turn off Jaws or NVDA and try tabbing tto the widget and pressing enter.
4. Notice that the widget now expands.
5. Reload Jaws or NVDA and find the "Summary" button that is now expanded and press enter or space to collapse it.
6. Notice that the widget doesn't collapse, neither visually nor in the Jaws / NVDA virtual buffer.