I have found the following keyboard traps in Jira Portfolio which make it in accessible to keyboard only users. The focus becomes trapped in a menu and you cannot escape it without using a mouse. The normal Jira keyboard shortcuts did not appear to be effective.

1. In a Plan, in either the Backlog, Team, Release, or Reports view, when you use they keyboard to enter a column filter, you can modify all of the filter selections, but you cannot exit the menu for filter selections using the keyboard only.

2. In a Plan->Backlog, at the bottom of the page, when the schedule is visible, if you enter the schedule settings you cannot escape the setting menu without using the mouse.