October 2016
As reported in this thread in the Official Forum, obols are not counting from Trick-or-Treaters sometimes.
Using the candy bag to jump to the kids and auto tap them, or having cash & XP collecting at the same time can cause the obols to not count.
I verified this in my own towns.
October 2016
I have not noticed this but was not really paying attention. I am collection the coins from trick or treating now using the character finder just in case.
October 2016
I posted this in our EA forum but posting here.
I've been watching but have not noticed a glitch. I also reached out to the EA team, and they found the Obols are behaving correctly and are getting collected as well. Matter of fact I looked at my obel count, I know on collecting the trick or treaters I get 22 obels. I used the pumpkin method and after clearing each trick or treater the numbers added up correctly.