Hey Stella,
My understanding is that each member’s monthly $5 gets distributed to the writers of the stories they clapped for that month based the number of claps they gave a particular story as a percentage of the total number of claps they gave that month.
For example, if a member claps 100 times in a month, and 50 of those claps were for one story, then the author of that story will get $2.5 from that member.
This is why there doesn’t seem to be a clear explanation for your payments given the data you have. Missing information includes whether each fan is a member and how many claps they gave your story relative to all the the other claps they gave.