Hi Peter,
Thanks for using Syncfusion products.
We have checked the reported query from our end. You can bind the DataTemplateSelector to the ItemTemplate of the TreeView. We have prepared the sample to replicate the issue while scrolling the items, unfortunately the reported issue does not replicated at our end.
For you reference we have attached the sample and you can download it from the below link.
Please check the reported issue occurs in our sample. If the above sample does not meet your requirement then, Could you please modify the above sample to replicate the issue which would highly help us to analyze the query better and provide an appropriate solution.
Regards,
Rawoof M.