Reproducible in this demo: https://demos.telerik.com/kendo-ui/spreadsheet/datasource
The data cleared by the "undo" shortcut is saved and sent to the server
A different behavior is exhibited if the data is pasted over the row header instead of the row's first cell. Follow the same steps, but on step 3. instead of pasting over the first cell, paste the data over the row 79 header. After undo and then clicking "Save", the fields have null values.
No data is sent with the request