Hey @MutedJam,
You are my hero of the day !!
I tried in the desktop App, as @Jon has mentioned (NewbyQuestion > to have more executions left in cloudApp. => so it took a little longer because of the different Credential Oauth2 with Google Calendar)
And there is after activating the Workflow really only the one (1) «NEW» Event => Created before a few seconds!!
Thank you a lot for your help, you saved me hours of coding and try&error !!!
Martin