Nested dropdown not showing down-chevron

[stefanodavid]

Describe the bug

A collapsed nested dropdown will not show the "down-chevron" to expand its content.

However, the "up-chevron" to collapse the dropdown is shown correctly when the dropdown is expanded.

To Reproduce

Copy and paste the following rst code and compile

.. dropdown:: a dropdown

   sample dropdown

   .. dropdown:: a nested dropdown
                 
      sample nested dropdown w/o chevron

Expected behavior

A down-chevron should be displayed to make clear there is some hidden content.

Environment

• Python 3.7.3 (on Debian Buster)
• sphinx-panels 0.5.2
• theme: I tried with both alabaster & rtd

Additional context

--

[welcome[bot]]

Thanks for opening your first issue here! Engagement like this is essential for open source projects! :hugs:
If you haven't done so already, check out EBP's Code of Conduct. Also, please try to follow the issue template as it helps other community members to contribute more effectively.
If your issue is a feature request, others may react to it, to raise its prominence (see Feature Voting).
Welcome to the EBP community! :tada:

[chrisjsewell]

This will essentially be closed by https://github.com/executablebooks/sphinx-design, where it has already been fixed