Not able to Partially fulfill Non-Shippable Bill Only items

Summary:

Not able to Partially fulfill Non-Shippable Bill Only items

Content (please ensure you mask any confidential information):

We have business scenario of adding Non-Shippable item lines along with MFG products on Sales Order.

Further business would like to partially fulfill Non-Shippable lines like Product lines and fulfill remaining quantity later.

When we are Splitting Non-Shippable Billable fulfillment line, system is not allowing Split (Orchestration not on Manual Task error).

Also not able to edit/change/update Quantity on fulfillment line.

We need to bill partially for Non-shippable line.

(FYI-Custom Orchestration definition involving manual scheduling task is also not working)