form group: the field "{name}" is owned by m...

Warnings reference › form.group.duplicate-field:*

Identifier

form.group.duplicate-field:*

Raised by

form

Since

1.100.0

What happened

Two member forms of one createFormGroup both report a field with this name, so getValue() would merge them over each other and setValue() could not know which member the key belongs to. The group keeps the first member added as the owner: getItem(name) and setValue() write to that member, and the later member keeps its own value.

The fix

Give the duplicated field a unique name, or drop it from one of the members.

The smallest fix

createFormGroup([formA, formB]); // formB must not reuse a field name formA already owns

Reference

Covered in full at the API reference.