Hello, 

I'm having a few issues using custom summaries with nested groups. See details below and provide assistance if possible, any help is appreciated. You will find a stackblitz reproduction of the issue at the bottom.

Scenario: Show only the sum of child level items that are nested in groups.

Problems:

• Summary shows on each child level.
  • Example:
    • Level1
      • Child 1
      • Child 2
      • Summary of child values should show here and does
    • Summary of all Level 1 children should not show here but does
• Custom summary to only show the sum value has been defined but all summary values still show

Notes:

• The console shows an error of "ERROR TypeError: classRef is not a constructor"
  • Stack Trace:
  • HelloComponent.html:4 ERROR TypeError: classRef is not a constructor
    at IgxColumnComponent.set (column.component.ts:633) <-- IgniteUI
    at IgxColumnComponent.propDesc.set (watch-changes.ts:47) <-- IgniteUI
    at IgxColumnComponent.propDesc.set [as summaries] (watch-changes.ts:75) <-- IgniteUI
    at updateProp (provider.ts:448) <-- StackBlitz
    at checkAndUpdateDirectiveInline (provider.ts:196) <-- StackBlitz
    at checkAndUpdateNodeInline (view.ts:429) <-- StackBlitz
    at checkAndUpdateNode (view.ts:389) <-- StackBlitz
    at debugCheckAndUpdateNode (services.ts:430) <-- StackBlitz
    at debugCheckDirectivesFn (services.ts:391) <-- StackBlitz
    at Object.eval [as updateDirectives] (HelloComponent.html:14) <-- MyComponent
• I'm sure I'm missing some type of wiring but can't spot it. I've followed the examples found at https://es.infragistics.com/products/ignite-ui-angular/angular/components/grid/summaries.html#summaries-with-group-by
• The "classRef" error shows up even without the grouping.
• The structure of my reproduction is partly pulled from my personal solution that this problem shows up in.

Reproduction of Issue:

• https://stackblitz.com/edit/angular-9g52kx