a scale's "mid" ({mid}) is outside its min..max range, so it was ignored.

Warnings reference › formatting.scale.mid.range

Identifier

formatting.scale.mid.range

Raised by

The grid (core)

Since

1.68.2

What happened

The midpoint lies outside the scale's own domain, so there is no position on the ramp to pin it to. The stops are spread evenly instead, and the scale is drawn uncentred.

The fix

Put mid between the scale's min and max, or set the domain explicitly so that it contains the midpoint.

Reference

Covered in full at the API reference.