After v20.0.0 update and the removal of kendoGridGroupBinding directive, there is a new bug that was not there before.
If you are in group mode, and you programmatically change row data, the data does not reflect the changes visually, unless you collapse the groups and re-expand them again to see the new changes.
This problem only started after removing the kendoGridGroupBinding input or directive.
*Update: this problem only happens when virtual scroll is on.
I have also noticed that selecting a row is glitchy when the grid is grouped and sorted, especially when it is initially sorted and grouped.