Appstream apps that act as a client in a client-server model where an EC2 instance is the server

There are a few apps that are part of an app suite I want to provide to my end users via Appstream, but these apps are not standalone in the sense that they rely on a shared database for end users. Meaning the end user uses a client instance of each app (run on a separate workstation machine), yet the apps rely on a server instance of the app suite (run on a server machine) which maintains the database and network folders, etc.

If we were to do this in an on-premise scenario, we would install the server config of the app suite (with SQL Sever Express) on a server machine (running any of Window 10/11 or Windows Server 2019). This server machine installation also creates special Windows environment variables and shared network folders. Then we would install the client config of the apps in the suite on each workstation in the office LAN. The client instances of the apps almost act like dumb terminals wherein they present a UI and use a config to connect to the server instance where the database is and all the business logic actually happens.

Therefore, I was thinking maybe I could create an EC2 instance to run the server instance of the app suite, and then configure the VPC, security groups, and required network config so that this EC2 instance can communicate with an Appstream fleet that runs the client instance of apps.

Is this at all possible?

I've tried to do this, and so far I've:

• Created EC2 instance with Windows Server 2019
• Configured the VPC and NAT following these instructions ttps://docs.aws.amazon.com/appstream2/latest/developerguide/managing-network-internet-NAT-gateway.html
• Installed the server instance of the app suite on the EC2 instance, and tested that it works properly on that instance.
• Launched the Appstream Image Builder using the latest Windows 2019 Base ensuring it's part of the same VPC and Security Group as the EC2 instance.
• This where the problems begin.

In the Appstream Image Builder instance, I cannot see the EC2 instance File Explorer > Network. Also, every time I try to change the Network Discovery settings in the Image Builder instance (e.g. to switch it on for Private networks), it reverts the settings after clicking Save.

If what I'm trying to do is indeed workable, then what do I need to do enable the Appstream instances to communicate with the EC2 instance?