There are two service plans, both have billing model
Charge Before Billing Period, bith have 1-year subscription period. The frst service plan is billed annualy, the second one - monthly. The subscription with additional resources purchased switched from the first service plan to the second one.
Change order has incorrect duration for resource recurring fee for the destination service plan (e.g. 0.08 month instead of 1 month(s)).
The issue is caused by #PBA-79565 "Incorrect duration for resource recurring in plan switch order"
The bug is to be fixed in upcoming OSA update.