The grid (core) · console.warn

no column "{id}" to ungroup.

Printed by The grid (core), prefixed [lattice], since 1.29.0.

Warnings reference › columns.ungroup.unknown:*

Identifier: columns.ungroup.unknown:*
Raised by: The grid (core)
Since: 1.29.0

What happened

ungroupColumn() named a column the grid does not have, so nothing was promoted and the band structure is unchanged. A column that is already at the root is not an error and says nothing.

The fix

Check the id against grid.columns.all().

Reference

Covered in full at the API reference.