Looks great.... but I need/want 2 way with Outlook. MS bought Wunderlist and buried it, now using ToDo, integrations with Outlook ok (2 way) but functionality bad (ugh). So frustrating.
The only thing I can think of is check that when you subscribed to the Todoist calendar feed you have it set to be stored in iCloud not “on my Mac”. If it’s only stored on your Mac it will not show up on your other devices.