Requirement:
Since CLASS is in the main line record, whatever value is populated, will be the Class shown on the GL Impact for all item lines. We might need to switch to using Class as an item line column so that it will link the proper Class value per respective GL account.
Solution:
There is an accounting preference that allows this type of scenario.
❗️ Note:
After you enable the CLASS per line, you have to make sure to re-login once. Then only all preference will work