Hi @peter.zhou sorry for the late response.
( Apparently when a message is edited it doesn’t send notification…)
will get back to you ASAP
Thanks
Thank you so much for your support!
I added more logs as the logs you suggested and eventually we figured out the problem.
I will spare the details, but in short, the custom calculation works as expected!
(The problem was that the Excel file we got was already “damaged” and this was the root cause for this issue.)
Thanks again 
Ori
that is ok, well done.