Facing this issue in an app I just built. I have a form with a few fields that are based on choice columns in a SharePoint. They work fine when I Allow searching in them, but as soon as I disable it they fail to show any content. Funnily enough, it seems to only happens for some of these columns, those where I cannot add new values manually in SharePoint.
Example with Allow searching on:

Example with Allow searching off:

It does not happen with the classic control. Any idea as to whether I might be doing something wrong?