In beta, when I have a pane set to List view, change to a different board and then back, the List view pane is changed to Outline view.
Also when I create a new board and then select List view for a pane, it creates the pane as an Outline view.
Saving default view for a board with a List view pane, switching away and then back, and then restoring default view does not restore the List view. The pane remains an Outline view.
Maybe this could be fixed along with the bug where Email panes (such as one set to show Starred) revert back to All Accounts when switching to another board and back.