In general, the fact that the model is not correctly bound to the values from the editors means that there is an issue with the binder. It is important to point out that with the latest version the scenario of a grid inside a Kendo UI Window performs all CRUD operations correctly.
Also, you should make sure that there is a model.id setup that would inform the grid which field is the unique identifier.
Virtual Classroom, the free self-paced technical training that gets you up to speed with Telerik and Kendo UI products quickly just got a fresh new look + new and improved content including a brand new Blazor course! Check it out at https://learn.telerik.com/.