Minus "-" keyboard shortcut does not expand/collapse issues in sprint if there is just one swimlane. It only works when there are multiple swimlanes in the sprint.

Workflow 1

• Create a Sprint A with a bunch of tasks 1, 2, 3 with no sub-tasks on any of those. 
• Navigate to the Scrum Board and go to the Sprint A and hit the " - " key to toggle between expanding and collapsing swimlane and nothing happens. 
• This seems to be because there is just one swimlane which includes all the issues with no subtasks. 

Workflow 2

• Create a Sprint B with a bunch of tasks 4, 5, 6 with sub-tasks created on all of those tasks. 
• Navigate to the Scrum Board and go to the Sprint B and hit the " - " key. It collapses but when the user clicks on the "-" key again to toggle between expanding and collapsing swimlane, nothing happens. 
• This is also because there is just one swimlane which includes all the issues with subtasks. 

Workflow 3

• Create a Sprint C with a bunch of tasks 7, 8, 9 with sub-tasks created on a couple of those tasks and keep a couple of tasks without any sub-tasks.
• Navigate to the Scrum Board and go to the Sprint C and hit the "-" key to toggle between expanding and collapsing swimlane and it expands and collapses the swimlanes correctly.
• This is because there are now two swimlanes, one which includes tasks with subtasks and another one which includes tasks without it. You can see below that the top swimlane is for tasks with subtasks and the bottom one which says "Other Issues" shows tasks without sub-tasks.