source.mode "derived": `follow` is ignored when `from` is a union of several grids - each entry carries its own `follow` instead.

Warnings reference › source.derived.union.follow

Identifier

source.derived.union.follow

Raised by

The grid (core)

Since

1.51.0

What happened

In a union each parent decides for itself how much of its grid to contribute, so a single top-level follow has nothing to apply to. It is ignored and each entry's own follow is used.

The fix

Put follow on each entry of the from array.

The smallest fix

from: [{ grid: a, label: 'A', follow: 'filtered' }, { grid: b, label: 'B', follow: 'all' }]

Reference

Covered in full at the API reference.