opened
ChronosSF
username_0
## Description  
Expanding a child island and trying to move through it with the UP arroy key while its rows are at the top of the virtualization container is broken.

 * igniteui-angular version:  9.0 (*doesn't reproduce in 8.2*)
 * browser: n/a (surely happens on Firefox)

## Steps to reproduce  

1. Open the hierarchical grid updating sample
2. Expand the 3rd row
3. Scroll all the way down on the parent grid and try to navigate through with the Up arrow key

## Result  
While the focus is in the child grid it gets lost (or sometimes even two cells with focus can appear)

## Expected result  
Navigation should not get interrupted


## Attachments
Navigating through child islands with the UP key is broken
issue
closed
ChronosSF
username_0
issue