Only three options are displayes and there's no indicator that there's more options available
Scrollbar for Dropdown

FYI: Scrollbar visibility was set that way only in docs:

When you're using Dropdown in your project it works fine.

there's no reason for it to be that way in docs.
could you change that?
Yeah, I'm not Carbon team member, but why not 馃槃
But, please, create Issue for this here, in docs repo, and ask Carbon Team for this. I guess that they had some reasons for disabling visibility of scrollbar.
closing due to this issue being opened in the correct repo here https://github.com/carbon-design-system/carbon-website/issues/1095
Most helpful comment
FYI: Scrollbar visibility was set that way only in docs:

When you're using Dropdown in your project it works fine.
