And issues with the first_visit event in GA4 and BigQuery

[magdalenamiler]

Hi, I noticed that GA4 shows an average of 3,5 first_visit events per active user. How is this possible?
Additionally, after analyzing the data in BigQuery, found that some users (with consent) don’t have any first_visit or session_start events at all. Do you have any idea what might be causing this issue and how it can be resolved?