SAP issue - I use B1UP Content Creator to add multiple Tabs on to an exting window. They work but the they do not activate/get focus

This is a known issue on SAP system windows that have a limitation of only being able to visually show up to 9 tabs/panes per window. It can also happen on sales and purchase documents with fewer tabs (because the item/service matrix behind the scenes actually use 4 panes).

SAP have more information on the issue in SAP Note: 885041 (The note states a way to fix it but that only apply to add-on windows and SAP have not applied the fix to their own windows).