How to Hide Fields in Published Feature Service

[KE]

I have published a map service from an ArcGIS Pro project where I have turned off most of the fields in most of the layers.

I expected only the visible fields to be available in the feature service, but when I pull the service into a map and open the attribute table, all the fields are visible.

Is there a way to hide the fields before publishing?

I am giving the rest endpoint to a third party for use in a map, so I can't hide the fields myself in the map.

We are using Portal, but the server I am publishing on is internal.

[AKRRMapGuy]

I know this is an old post but did you ever find a solution to this?