Access and Update Metafield User Field data

I am trying to retrieve and update a specific set of metafields for product variants. I am able to query them via the api but some do not display. One that doesn’t display shows that there are 0 metafields but the field does display on screen.

I believe I have been able to successfully update ones that I can query via the api but not the ones that do not show.

What is the best way to manage the metafield data? I am using the REST API.