SNP hueristics with Transportation Lane

Dear

Would I ask you about the problem:

When run SNP heuristics ,there is no vendor in created PR,but if input demand as [Distribution Receipt(Planned) directly in Planning Book, Vendor is assigned in PR correctly.Is any idea about this issue?

Master check:

1.Procurement Type 'F'

2.Infor record is OK (ECC)

3.Transportation lane is correct as other no problem transportation lane(APO)

Thanks &Regards

Ellen