[Bug]: Cell merging custom strategy is adding additional groups when splitting merged groups

[dkamburov]

Description

Scrollbar and records count is increasing when splitting groups.

• igniteui-angular version:
• browser:

Steps to reproduce

1. Go to https://www.infragistics.com/products/ignite-ui-angular/angular/components/grid/cell-merging#demo
2. See the video attachment
3. Start clicking on cells from the first and then from the second column

Result

Scrollbar is increasing, it seams that in some scenarious there are additional records added(dupicaded)

Expected result

Scrollbar and record count should remain the same

Attachments

cell-merge-duplicate-rows.mp4