I created a Blazor Wasm app using the Syncfusion Blazor Template Studio. I added a single Diagram component.
I did not have this problem in v220.127.116.11
Build and run.
Click on the Diagram nav link.
Visual Studio: Version 16.6.0 Preview 2.1
Dotnet: 3.1.300-preview-015048 (I also tried 3.1.200, 3.1.201)
Blazor: 3.2.0-preview3.20168.3 (I also rolled back to preview 2)
The zip file contains
1. Screen capture of the browser timing window
2. The browser consloe log
3. The app project.