Apologize for the delay and thank you for the provided code snippet.
After a thorough examination of the code, I noticed that the grid uses both BindTo and Ajax binding which is actually not supported. Since the grid seems to enable data editing I would recommend using only Ajax binding. Attached you can find a sample project (that can be used as a starting point) that follows the described scenario and illustrates a possible realization.
Furthermore, try setting the CRUD operations in the grid's DataSource. Here is an example: