Script to automate data load rule not recognizing variable

Summary:

I am trying to write a script that calculates and then uses the calculated period to use as the start and end period in the data load rule. The period should rollover to the next period on EOM - 3 days, so March 27 would calculate P3-FY26 and March 28 would calculate P4-FY26. This part of the rule works and calculates the correct period, but when I go to grab that period to use in the data load rule it does not work. It grabs a blank or nothing. The script is able to log into FCCS, but then