If you use Item Placement Tool custom tabs in either Item Master data or Business Partner Master data forms, you will notice that you're missing SAP's own system tabs if you open the forms from the main menu.
This is unfortunately an SAP bug in version Business One 10 PL 2011.
The problem has been informed to SAP and we're waiting for their fix. Any updates on the issue will be added to this article.
SAP is aware of this issue and we're waiting for an answer. The same problem occurs with SAP's own UI-tools.
SAP Have informed us that the issue will be fixed in SBO 10 FP2102 (Start March 2021)