Does not run once but runs on existing data

What are you trying to achieve?

I am setting up a scenario triggered by watching Google Calendar, to then create a database row in Notion. The scenario does not run when I click run once, nor does it run on a schedule, but when I run it on existing data, it works great. Any tips?

Steps taken so far

I have already set choose where to start as from now on.

Hi makellama, did you select the right calendar? Make sure to choose the right calendar and to add the events to that calendar