Hi, @SGarneau ,
From the surface, it does look like everything has been set up correctly. I would be interested, though, in finding out how the custom properties are being updated. Is it possible that the formatting of those properties are causing a glitch in the calculation?
It will be beneficial if you could share a screenshot from a specific deal (of course, removing any sensitive information) showing the values for the custom properties, based on which you have the calculation. Also, further context on how those are updated can be valuable, too. Is it via a workflow or in another way?
Thanks,
Eli