If you use the tab key to navigate through Bootstrap tabs, only the active tab can receive focus. The other tabs get a -1 tabindex attribute, although it's not in the markup. It's not an issue in standard Bootstrap 5 demos, so something unique seems to be happening in our use.
But you can actually switch from one tab to another using left/right. Which is better IMO, you can skip the whole tab list with tab. I thought this behavior was expected :)