NN Shows 50012450 then why does the Requisition starts with 1

the Next Number P0022  - for 43 product code has been setup for requisitions 50012450.

so when a new requisition is created it should auto generate the NN +1 = 50012451.... However it started new requisitoions with a 1, the 8. I checked the Check Digit used is not clicked it is blank.

For PO the last number is 30012300 - new PO created from requisition created as 30012299.

I checked diff application for next numbers and they are not set up anyway else except the P0022.  Please could some kindly assist... thanks