Have an update:
Initially I did not have Google calendar installed on Note; only S Planner. In Google sync calendar was checked. In S Planner mycalendar was the
@gmail.com calendar. But this was rsulting in updates not flowing between teh S Planner and calendar on Google
Then I wrote this post..
Yesterday night I also installed Google calendar app on Note, and voilla... S Planner and Google Calendar (both app and actual web Google calendar) are now in sync.
So, my conclusion is that for S Planner and Google Calendar you need; last 2 sound obvious....
1. Both S Planner and Google Calendar apps installed on Note;
2. Google calendar sync turned on
3. Google calendar chosen as the calendar on S Planner