The grid (core) · console.warn

grouping ignores unknown column "{col}".

Printed by The grid (core), prefixed [lattice], since 1.0.1.

Warnings reference › source.group.*

Identifier: source.group.*
Raised by: The grid (core)
Since: 1.0.1

What happened

A groupBy entry names a column the source cannot read, so that level is dropped from the grouping. The remaining levels still group, so the tree is shallower than asked for rather than absent.

The fix

Check the column id in groupBy.

Reference

Covered in full at the API reference.