Microsoft ToDo details pane won't stay open after sub-task actions

[sklebold]

I'm using the Windows 10 app version of Microsoft ToDo.  Recently the task details pane keeps closing immediately after taking action on a sub-task (e.g. marking a sub-task complete, or entering a new sub-task).  In the past, the pane would stay open after these actions.  But now, working with a list of sub-tasks is painfully tedious, as the pane needs to be re-opened after every sub-task action.  Is this an error, or a new "feature"? 

[#2]

Additionally, the same thing happens in the Today pane - taking any action on tasks that appear in the Today suggestions pane (such as marking one of them complete) causes the pane to immediately close. (Another unwelcome "feature".)

[#3]

This issue now seems to be magically fixed.

[#4]

This issue is happening again, starting this morning.  It has not been an issue since fixed in 2020.