@Volker_E The following document (fix.pdf) shows where and how to fix the focus issue for the badges. Me and my team member have run out of time to work on this issue, so we're leaving the information we gathered while working on this issue. I also attached the entire .less file related to the badges with the changes in them (mw.echo.badge.less).

@Volker_E I was prototyping what changes can be made to the icons to set a focus to the icon. I determined that the #pt-notifications-alert and #pt-notifications-notice which control this cannot be used with 'focus' and instead required 'focus-within' to affect the icons on a tab highlight. I will take a look at the link you sent me and make changes following those standards. If you can direct us to the particular protocol to make those changes to what I assume is the 'resource-loader' we would appreciate it. In the meantime, I'll update if I come across any other issues.

When navigating through the page with the tab key, this solution sets a light blue border around the notifications badge.