Hi, this is actually working as expected. If you have null values within your field. By default, it is not supposed to show a label, rather empty like you are seeing now. In 4.22, it automatically added this (this was the actual bug), if you wish to show a label, you will need to set it in the form's field input like this,
input: {
type: "combo-box",
showNoValueOption: true,
noValueOptionLabel: "No value"
}
I've updated the codepen with this as well, https://codepen.io/hgonzago/pen/RwxZLqB?editors=1000