Siri/iOS Shortcuts suddenly cannot create To Do tasks

I have one Siri/iOS shortcut that I use all day long to capture my thoughts and tasks.  At the end, it takes input to the shortcut and creates a To Do task.  It has worked for months and months but, suddenly, starting yesterday, I'm getting errors like "Could not run Add Task - There was a problem communicating with the app."

Any ideas?  I've tried creating new shortcuts, I tried creating a shortcut from To Do (in the settings) - all attempts fail.  I really rely on this, and need it to work again!

Thanks for any ideas...