Based on your comments about custom duplication logic as well as duplication of items in buckets, it sounds like you might need/want to also hook into some of the events / processors related to item duplication. 

```xml
<uiDuplicateItem>
	<processor type="Sitecore.Shell.Framework.Pipelines.DuplicateItem,Sitecore.Kernel" method="CheckPermissions" mode="on"/>
	<processor method="CustomMethodName" mode="on" type="Custom.Project.Web.Pipelines.DuplicateItem.CustomDuplicateItem, Custom.Project.Web" patch:source="Custom.config"/>
	<processor type="Sitecore.Buckets.Pipelines.UI.ItemDuplicate, Sitecore.Buckets" method="Execute" mode="on" patch:source="Sitecore.Buckets.config"/>
	<processor type="Sitecore.Shell.Framework.Pipelines.DuplicateItem,Sitecore.Kernel" method="Execute" mode="on"/>
</uiDuplicateItem>
```

More info on events can be found in this older documentation [here][1]. Inspecting your ShowConfig.aspx will also reveal other possibilities with events. For example:

```xml
<!--  Event hook after duplicating an item into an item bucket.
           Args: (ClientPipelineArgs) Args ->  -->
<event name="item:bucketing:duplicating" patch:source="Sitecore.Buckets.config"/>
```


  [1]: https://doc.sitecore.com/xp/en/SdnArchive/Articles/API/Using%20Events.html