How to Load Custom Hierarchy for Customer Dimension while using Key Customer Group

Summary:

User Defined Hierarchy for Customer is lost after Key Customer Group loading.

Content (please ensure you mask any confidential information):

We are trying to load the Key Customer Group and have tried all 3 values for aggregation_level, basically 1, 2 and 3, Before loading the Key Customer Group, on Customer Name, we had a Hierarchy called Forecast Customer Group which also has similar, but additional level called Sales Channel.

Once we used the KCG File to load the KCG - The User Defined Customer Hierarchy disappeared, each of the iterations above, we loaded Bookings and Shipments History, right after the KCG load, following a UserDefined Hierarchy load for the customers.