Never mind. I just figured out how to check off subtasks...
In the pop-up round-button menu of the task, click 'Change completion status'.
Shortly thereafter, I figured out how to undo that when necessary...
Click the 'Show details' (edit) button in the abovementioned pop-up menu. Then in the 'Edit Task' window, click on the little round light gray circle (with a white check mark inside of it) at the right of the subtask in question.
Thought I'd share my findings so others could possibly benefit from them. :)
Thanks for sharing, Bren. And we greatly appreciate your patience and understanding on this matter. Feel free to contact us again if you need any further help!
In the pop-up round-button menu of the task, click 'Change completion status'.
Shortly thereafter, I figured out how to undo that when necessary...
Click the 'Show details' (edit) button in the abovementioned pop-up menu. Then in the 'Edit Task' window, click on the little round light gray circle (with a white check mark inside of it) at the right of the subtask in question.
Thought I'd share my findings so others could possibly benefit from them. :)