On Internet Explorer-11, UI is getting blocked while performing comparatively fast data entries, it is not only too slow but values are getting truncated as well.

1. Open https://demos.telerik.com/kendo-ui/spreadsheet/index in IE 11

2. Start editing cells C3 to C12 and enter value 1234 in each cell as fast as possible

3. 1234 enter, 1234 enter , 1234 enter and so on without waiting for UI rendering completion as UI freezes for few seconds, and then all cells get updated in one go

4. below is the result, few cells are having wrong values 

5. Its very serious issue

Note: Excel 365, Excel and GoogleSheet works fine in such cases