Hi Johnathan,
Thanks for using Syncfusion products.
We are able to reproduce the issue reported by you in our end and the issue is due to updating the view the view area of Diagram control. We suggest you to not update the view area of diagram while creating nodes. We have modified the RadialLayout sample to achieve your requirement.
Here is the sample:
CS1274778780.zipPlease try the above sample and let us know if you have any queries.
Regards,
Amsath Ali. M