I found a strange behavior with the latest packages (.Net Core 3.0 preview 8, Syncfusion.EJs.Blazor 188.8.131.52.Beta) with the dialog component.
I attached the sample that reproduce the issue. Just run it. If you click on the Open Dialog button, it works. Then you can click on Ok or Cancel button and dialog will close.
Now, stop the application. Uncomment the line 30 in Index.razor file
Line 30 :
// await JSRuntime.InvokeAsync<object>("window.testCallJs.startCallJs");
Then run the app again. Click on the Open Dialog button. The dialog opens. But if you try to close it with Ok or Cancel button, it doesn't work.
If you take a look in the Index.razor file, you will see that I tried to use DialogEvents, but without any success.
This code worked when my application was running under .Net core 3.0 preview 7 and syncfusion 184.108.40.206.