WebDBGrid navigation problem

Good afternoon to all,
in a web test application i use a WebDBGrid to show some data.
All work fine, the data is displied as expected and i can scroll the grid with the horizontal scroll bar (i have more than 50 field).
Now the test:
Perfom any query in order to get 1 record
It is well visible and all cells are filled according with his data.
Using horizontal scroll bar move to rigth, few cells.
Select one cell.
Move the selected cell with left arrow to first cell
Move the selected cell with rigth arrow.

I get this error

Uncaught TypeError: Cannot read property 'cells' of undefined | TypeError: Cannot read property 'cells' of undefined at Object.GetCellElements (http://localhost:8000/VM75WebClient/VM75WebClient.js:66866:42) at Object.GetVisibleColCount (http://localhost:8000/VM75WebClient/VM75WebClient.js:66998:19) at Object.HandleKeyDown (http://localhost:8000/VM75WebClient/VM75WebClient.js:67342:73) at HTMLDivElement.cb (http://localhost:8000/VM75WebClient/VM75WebClient.js:238:26)
at http://localhost:8000/VM75WebClient/VM75WebClient.js [66866:42]

This happend every time the right arrow key is pressed.
Also, if i still press the key, the selected cell change (move to next cell on the right) and "goes out of the grid" widthout scroll.

Can you reproduce it?

Delphi 10.4.1, last web core version.

Thank's for attention