After trying your sample on three different computers, we realized why it was not working.
The sample is not working with this version of the Syncfusion dlls: 13.3451.0.7 (available for trial)
it is working with this version: 13.3451.0.18 (community license)
Are you planning to update the dlls available for trial purpose? It would be a good if they are not the latest.
In the meanwhile, we'll continue evaluating the grid with the community license dlls.