Blank General Modification GL is picked for WRX in MIRO Document

Hello Friends,

Need an urgent help.

PO type - Asset PO

Acc Assgn Cat - Investment (I)

Doc Posted in MIRO transaction.

In OBYC -> for WRX transaciton, I can see General Modification is selected in the "Rules" Tab.

In the Accounts screen there are 4 Gen Modification (one is blank and 3 lines with Gen Modfcns) are maintained.

User is expecting GL account from second line (ie, with zzz Gen Modfn->GL), but system is picking First Line (ie, Blank Gen Modifcn ->GL)

Could you please help on GL determination for General Modification?

Thanks in Advance!