Grid - Errors thrown when toggling/ungrouping FinJS sample in React and Blazor.

[skrustev]

1. Open the https://www.infragistics.com/blazor-client/grids/grid/finjs sample
2. Ungroup the last group

Error is thrown.
Also:

1. Open the https://www.infragistics.com/react-demos/grids/grid/finjs
2. Toggle grouping a few times

Eventually error is thrown as well.

[skrustev]

Appears to be fixed.