Order Guide variables do not cascade in the Service Portal. Although the variables on ordered items inherit the values of the identically named variables in the order guide in the regular Catalog order guide, they do not do so in Service Portal.
Steps to Reproduce
Create an order guide.
For more information, see the product documentation topic Create an order guide.
Select the Cascade Variables checkbox and click Update.
For more information, see the product documentation topic Cascade an order guide variable.
Create variables on the catalog items that match the names of the corresponding variables in the order guide.
For more information, see the product documentation topic Service Catalog variables.
Open the order guide in Service Portal.
Populate the variable in the Order Guide (which appears at the top of the page).
Note that the value of the corresponding variable in the included catalog item is not automatically changed to match.
This issue has no workaround. If you are able to upgrade, review the Fixed In field to determine the versions that have a permanent fix.
Related Problem: PRB686448