Navigating to another group board breaks navigation sidebar

• Navigate to group boards.
• Select another board from the dropdown.
• The navigation sidebar refreshes. It should not. It should remain static (and selected on Boards).

changed milestone to %10.0

added ~579550 regression labels

added Discussion label

added frontend label

assigned to @lbennett

created branch 3397-navigating-to-another-group-board-breaks-navigation-sidebar

mentioned in merge request !3010 (merged)

closed via merge request !3010 (merged)

mentioned in commit dda69dbc

mentioned in commit 31d1401e