Understanding and Resolving (not set) Data in Mixpanel Analytics

Hi Dear Mixpanel Community, I’ve noticed that in multiple boards within our Mixpanel project, a significant portion of data is labeled as “(not set)”—this includes not only the “Referrer” property but also other metrics and dimensions. I’m trying to understand the potential causes of this and how to resolve or reduce the occurrence of “(not set)” data across the board. Specifically, I’d like to know: 1. What are the most common reasons for data to appear as “(not set)” in Mixpanel across different properties and metrics? 2. How can I better configure my Mixpanel tracking to minimize the number of sessions or data points that are labeled as “(not set)”? 3. Are there any best practices for ensuring that information is accurately captured, especially for referral data, direct traffic, mobile apps, and cross-domain tracking? 4. Could this issue be related to missing UTM parameters, JavaScript blocking, or any specific technical issues I should check on my end? 5. Have others experienced similar issues across different boards, and how were they resolved? Any insights or recommendations on how to address this issue would be greatly appreciated! Thank you in advance for your help!