Hi @cls ,
Each survey should have a specific surveyId, you could try to find this surveyId and configure it in When a survey response is submitted.
Click Enter custom value to populate the obtained surveyId.
I can't use Survey123, so I'm not sure how to find surveyId. In general, as long as we click on the specified survey in the survey 123, the browser address bar will contain this parameter.
For example, we need to get FormId of MS Forms. Just click on this Forms and the FormId will be displayed in the address bar.
Image reference:

Hope it helps.
Best Regards,