Hello Martin,
We were using igxCombo within an IgxCellEditor using the same setting as showed in the official documentation. when you are new to the page and use any dropdown present in the grid it works fine but after you try to work with other dropdown in the grid the problem starts to come. problem is that when you select any option it does not reflect immediately, it comes when you scroll over dropdown list or close the dropdown.
Thanks,
Bala Murugan