Number range skips for follow on PO

Hi All,

We have noticed a very weird issue. We are on ECS and when PO is created as followon doc, the number range is skipped.

E.g. If the PO is created with number 100 then the next PO will pick the number as 103. We are not sure why this is happening. Kindly provide your expert views on the same.

Thanks,

Sunil