Hi Pierpaolo,
Greetings from Syncfusion support.
Query: “the event will be raised but you'll get a JavaScript error and the Grid won't go in edit mode”
We are able to reproduce the reported issue in your sample. Currently we are validating your issue, we will update you the further details by January 3rd 2020.
Till then we appreciate your patience.
Regards,
Vignesh Natarajan.