Fluent UI ComboBox allowFreeform

I have issues with a controlled ComboBox in fluentui from ms. I not been able to insert my own text, after insert and press enter the text disappears. The option selection works without problems.

Here a codepen: https://codepen.io/verhext/pen/jOrKOPe

 <ComboBox
    componentRef={comboBoxRef}
    defaultValue={selectedKey}
    selectedKey={selectedKey}
    label="Basic ComboBox"
    allowFreeform
    autoComplete="on"
    options={comboBoxBasicOptions}
  onChange={onChange}
/>

I don't know what I'm doing wrong in my code.
Thank you!

Combobox doesn't allow you to select any text value. allowFreeForm prop means that you can use manual search to select items.