Layer Data Source Not Recognized with Server

[PaulMcCord]

I'm attempting to publish a map service to ArcGIS Server from ArcMap. But when I Analyze within the Service Editor before publishing, I receive the warning "Layer's data source is not registered with the server and data will be copied to the server."

However, I have registered my geodatabase with the server, and when I validate my connection in both ArcCatalog and ArcGIS Server (in the Server Manager), I receive a green check mark next to my database indicating that I've registered my data with the Data Store.

The network that I'm working on is one where my desktop computer is where I am running ArcGIS Desktop (ArcMap and ArcCatalog), a separate machine in our network is where the Enterprise Geodatabase resides (where I am accessing the data for the Map Service), and a third machine is running ArcGIS Server.

I think the attached schematic is essentially the same configuration that I have when registering my data. This schematic was taken from https://enterprise.arcgis.com/en/server/10.5/publish-services/linux/overview-register-data-with-arcg... ("About Registering your data with ArcGIS Server" help file).

Could the issue be that somehow my connections between the three machines are untrusted and causing this warning? I'd really like to publish my service without copying the data to the server.

[KevinDunlop]

When you load the mxd in ArcMap what type of database authentication are you using?  If you are using OS authentication, your personal account might have access to the data while the account ArcGIS server has stored for that database might not.

[PaulMcCord]

Thanks for your response Kevin. I am using OS authentication. Is there any way I can check to see if the account ArcGIS Server has is able to access the database, or is there any way to ensure that all accounts have access to the database? The database was created by a previous employee, so I don't have all of the details of its creation; the same is true with the installation of ArcGIS Server.  Additionally, we have a separate team that is in charge of maintaining our databases (including SQL Server), so that installation was not done by me either.  

[ThomasColson]

Make sure that the service account running ArcGIS Server has read/write/connect to the DB. You can register SDE as a datastore, but publishing will check those permissions and fail if they don't exist.