Hi Nikolay, I ended up on this page because I'm noticing an issue in the keyboard navigation with virtual scrolling in my application. I just went to the example you offer and lo and behold, the same thing happens in the example. In my application, as I scroll down my grid using the keyboard, the row selection skips over one row every 40 rows. This is not obvious at first, but after I added a column containing a sequential row number, then it was more obvious to notice.
In your example above, I was able to reproduce this 3 times: if you use the down arrow, you will end up skipping Order ID 10340. The cursor jumps from 10339 to 10341. In Full Screen mode it skips Order ID 10343.
Is this a known issue? This is problematic for us because users have to review each row for quality control so skipping a row can mean a liability for us.