Hello YJ Kim,
Zach here with Mixpanel Support 👋 thanks for writing into the Community 🙂
I understand your concern about the delay in ID merge and its impact on your real-time onboarding funnel analysis. This delay is indeed a known behavior in Mixpanel due to the process of merging pre- and post-auth events. It can take up to 24 hours for the identities to be merged and for the funnels to show accurate results. This is because there is an ID Merge delay for the anonymous and identified user activity to be linked together across Mixpanel.
Unfortunately, there isn't a way to speed up this process within Mixpanel. The delay is inherent to the process of merging pre-auth and post-auth events, which allows Mixpanel to connect these events and see them as a single user performing those events.
Because of this delay, using Funnels for same day / real-time analysis is generally not recommended. The best practice would be to look at least a day back (24 hours) in your Funnels Date Range to allow the merges to settle. This would ensure that you're looking at complete data.
For debugging purposes, the Activity Feed view of a single user is updated in near real-time (less than 1 minute delay), so you can at least verify individual user journeys there.
Thanks for your understanding! Hope this helps at least confirm what you're seeing.
Zach
Mixpanel | Support Engineer