Hello,

A possible workaround that involves two complementary changes (apply both for the best result):

1. Remove the debounce for virtual/keyboard navigation — your 300 ms debounce makes the problem significantly worse. For a virtual scroll combo, debounce only makes sense for text filtering, not for the page-fetch triggered by scrolling/keyboard. With 300 ms + 400 ms simulated delay = 700 ms per page load, the keyboard easily outruns it.

2. Intercept keydown via JS and rate-limit arrow key events, as a client-side guard. A small JS snippet throttles the arrow keys so the component never receives a new keydown before the previous virtual page has had a chance to begin loading. This won't break slow navigation, since it's only active when keys arrive faster than the threshold.

REPL example that demonstrates the workaround: https://blazorrepl.telerik.com/wUaKwJYN35FxmqTw49 

Regards,
Ivan Danchev
Progress Telerik