rows were declared twice - as the top-level ...

Warnings reference › config.rows.duplicated

Identifier

config.rows.duplicated

Raised by

The grid (core)

Since

1.63.0

What happened

Two answers to one question. The top-level rows wins, because it is the shape every example uses and the one rows.load() writes to - leaving the source block's rows in place would make a later set('rows', …) disagree with the grid. Picking one in silence is how a host ends up debugging the rows they can see rather than the ones they declared.

The fix

Declare the rows once: at the top level, or inside source, not both.

Reference

Covered in full at the API reference.