Thanks for the update.
When clearing the cell content, it was saved as [Object object] which was the issues logged in the below feedback report and the same was fixed and included in v16.4.53. Please find the below sample and try to clear any cell content to empty and save it. Now it will be saved properly.
Also if you are trying to add new record in the grid with empty data source then we must specify the column type explicitly to avoid this problem.
<ColumnDirective field='OrderID' type="number" . . . ></ColumnDirective>
If the information didn’t resolved your problem please get back to us with more information on the problem you have faced.
Madhu Sudhanan P