When calling the update method on the grid the update is being called after read. When using a pop up modal to update a row that using a hidden member of the model as an id the display name isn't updated and the update call is actually firing off after the read so the value on the grid looks unchanged until you sort or refresh the page.
This sounds like a bug, Marco. Can you prepare a simple demo illustrating the issue and send it for further investigation via our forums or support system on telerik.com? Thus our support team will provide an accurate explanation/fix. Thank you for your cooperation.
the current work around requires the datasource to fire a client side event that forces the read method example : .Events(events => events.RequestEnd("manualUpdate")) the only reason i needed to do this was because the read was being called before the update.