Billing Schedule not generating properly using custom pricing values

Summary:

If we do not use pricing from the Pricing module, instead we pass a custom value for the unit list price in the payload while creating a subscription, the billing schedule that is generated for a monthly frequency, is not dividing the value by 12, instead the amount shown for all months is same as the unit list price.

Is there a way to configure this so that whenever a monthly billing frequency subscription is generated, the bill lines should show the amount divided by unitListPrice / 12.