ME_GUI_PO_CUST - change display options

Hi ,

I have implemented the BADI ME_GUI_PO_CUST and create custom fields in the custom screen of PO item. However, in ME21N, this new tab is not appearing. At the same time, it is appearing in ME23N. If i take a PO in display mode, the tab appears and then switch to chaneg mode, the tab disappears.

Please help?

Kind regards.

Pavel.