SSIS Package - A network-related or instance-specific error has occurred while establishing a connection to SQL Server

Apologies for posting this as a new thread but the original became a little muddled.

I have a very basic SSIS package with one SQL Task and one Data Flow Task. These tasks use one package-level OLE DB connection. I have the package and project set to EncrptSensitiveWithPassword. The package runs fine in Visual Studio 2019 but doesn't run in SSMS following deployment to SQL Server 2016.

I created the package locally on my standalone machine (I have no network account). My deployment method was to copy the DTSX onto the server. Using a SQL Server account with sysadmin rights I then used SSMS to import the file to the SSIS Catalog and also set up at SQL Agent job using the file system deployment method.

Both deployments give me the same error on execution.

A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online.". An OLE DB record is available.

Source: "Microsoft SQL Server Native Client 11.0" Hresult: 0x80004005 >

Description: "Named Pipes Provider: Could not open a connection to SQL Server [53].

I don't know why I get this connectivity error. I've tried using both the IP and static server name in my connection. I've checked that TCP/IP and Named Pipes are enabled in Configuration Manager, which makes sense otherwise I wouldn't be able to connect from my machine via SSMS.

I don't know what else to try. Any assistance would be great appreciated.