At mobile widths, Claro turns the vertical tabs into <details> elements. Within this, the <summary> element has aria-pressed and aria-expanded attributes.
These aria-pressed and aria-expanded attributes don't always reflect the proper state of the control.
On initial pageload, it is fine, but when you click any of them, both attributes are always set to false -- even if the details pane is expanded.
Steps to reproduce
1. Go to /admin/structure/types/manage/article page.
2. click on the vertical tabs on any device. On summary, aria-pressed and aria-expanded attributes don't always reflect the proper state of the control.
Check the attached video for same.

Comments
Comment #2
mherchelremoving
Comment #6
mgiffordLooks like https://www.w3.org/WAI/WCAG21/Understanding/name-role-value.html
Comment #7
gauravvvv commentedI have fixed the issue, provided patch for same. please review
Comment #8
smustgrave commentedTried replicating on 11.x on a node edit page and all the details summary aria-expanded and aria-pressed seem to be toggling fine. Can any additional steps be provided.
Comment #9
gauravvvv commentedI have updated the issue summary, with steps to reproduce.
Comment #10
smustgrave commentedSeems like something that we can easily add a test for to show the issue.