Open SQL with Custom fields in Standard table

Dear Experts,

I am facing a problem in ABAP Open SQL with custom field in Standard table.

I have added two custom fields in standard table. like below:

Standard table : AUFM (Goods Movement for order)

Custom fields:

ZZID       TYPE      MB_LINE_ID

ZZPID      TYPE      MB_PARENT_ID

When I trigger the open SQL on this table, first time it give me wrong data in custom fields, and after that or immediately I trigger the same sql, it give me correct data in custom fields.

I don't know what is the problem with custom fields.

Please help.

Thanks