Understanding Conversion Funnel Issues in Mixpanel: Need Assistance!

I'm trying to build a funnel using 3 events (Conversion callback -> Sign up -> Creation created). I'm using a filter of First time ever on Conversion callback, and when I do so, I see the conversion as 0 for a particular user. However, as I remove the filter, I see a 100% conversion for the same user. This did not make sense because when I checked the user profile, the user has completed all 3 events following the funnel criteria from the 1st time Conversion callback fired. Additionally, because there are multiple conversion callback events that fire, I searched for the event Mixpanel considers the first, and turns out it was considering the Conversion callback event 50 seconds post sign up as the 1st event. I'm super confused. I've recorded a quick loom here with more details. Would really appreciate some help here. This is really frustrating.