Hello,
The issue can be reproduced in a Grid with column virtualization enabled and Navigable set to true. Please run this REPL snippet
https://blazorrepl.telerik.com/QHusmyOJ027Rp5Ok38, click on any column, the appropriate row will be selected and the corresponding table cell will be focused. Try to navigate to the right by using Right cursor key - you will not be able to navigate through the whole table, values in last columns will not be displayed and the grid seems think they are in the same cell with User Number in my particular case. When you use Left cursor key and then the Right one again you will not be able to see even these columns headers.
I attached a small video to better demonstarte the issue on my particular machine.
Very thanks.
Miroslav