R42118 moved back line to back order

Hi,

Did anyone came across to a scenario where R42118 would release a line from backorder and immediately moves it back to backorder?

As per Sales order ledger:

1. Sales order was entered for  quantity 1, and was shippable with next status at 540.

2. Later, R42997 processed the line and moved it to backorder.

3. Later, R42118 processed the line and released the backorder (PDF output shows it as released and available quantity after release as -40), immediately again it moved back the line to backorder (no error reported in the same PDF).

If anyone has any inputs, please provide.

Thanks in Advance.

Regards