WO Entry doesn't attach "A1" cost component to Work Order

Facing a challenge to understand how this could happen as not be able to replicate in the testing environment:

Cost Method - 07 std cost $101.1

Cost component - 07 with work center activated/defined

A1 100

B1 1

C3 0.1

Place a work order , check product cost with P31022 and found only B1 and C3 has got value while A1 with BLANK.

The program to create WO is a customised one based on P48013, and it works fine most of the time and just occasionally created orders with this type of issue. Interestingly witness that the work orders with same item code/BP and created on the different days, some of them are good while some of them are not.