Extend My Inbox Purchase Order Item in Private Cloud Edition 2023 FPS01

[BerkSald1r]

Hello everyone,

We have a Private Cloud Edition 2023 FPS01 system and want to extend Purchase Order Item in My Inbox app. I extended C_PurOrdItemEnh view for that. I also cleaned metadata cache and app cache. But we couldn't see the fields neither in line items as default or detail page. Annotations are as follows. 

  @ui.lineItem: [{
            qualifier: 'PurchItem',
            position: 125,
            importance: #HIGH }, {
            position: 125,
            importance: #HIGH
            }]
  @ui.fieldGroup: [{
           qualifier: 'ItemDetails',
           groupLabel: 'Item Details',
           position: 50,
           exclude: false,
           importance: #HIGH,
           value: 'ZZ1_WBS_PDI' }]
  @ObjectModel.readOnly: true
  _ItemExtension.ZZ1_WBS_PDI,
  @ui.lineItem: [{
            qualifier: 'PurchItem',
            position: 130,
            importance: #HIGH }, {
            position: 130,
            importance: #HIGH
            }]
  @ui.identification:{ position: 17, importance: #HIGH}
  @ObjectModel.readOnly: true
  _ItemExtension.ZZ1_WBS_Description_PDI

I tried different version of annotations but we couldn't see them. We just see them in view settings tab in line items. You can see it as follows.

I extended C_PurchaseOrderFs to try to see if it comes to My Inbox PO header. It was came. I also extended My Inbox app for PR and PR items. It was also came. 

Is there any solution for that problem? Or is there a step I'm doing wrong? 

Thanks in advance for any input.

Berk.