h04x

I am referring to the TAB Button.

You can consult this example for what I mean:
https://demo.publishpress.com/advanced-accordion/
TAB does not select individual Accordion Tabs within a group. This can only be done with the arrow keys currently.

Here is an example of the correct implementation:
https://www.w3.org/WAI/ARIA/apg/patterns/accordion/examples/accordion/