The part that is confusing is I can go into the Railway dashboard and see my data but I cannot access it externally via CLI or application when I could before I tried changing the region.

Have you updated your connection strings after migrating?

If you're not using Reference Variables [0], you must do this manually, especially when accessing it externally.

[0] https://docs.railway.app/guides/variables#reference-variables

Referencing variables? Do I need a variable to reference one replication from another? My frontend is hosted elsewhere and I am trying to use the MONGO_URL="mongodb://username:password@viaduct.proxy.rlwy.net:port.

I am not referencing this variable from any other app or system other than having that URL in another apps env var (not on railway). I figured after the migration that same MONGO_URL would work. I check to see if it changed after the migration and it didnt.

Or is what you mean is I need to add something so my old replica can connect with the new one? Either way changing the setting in the settings and then re-deploying the database I wouldn't expect to need to add extra configuration. I would understand if some of the variables changed no problem but the variable that was spun up on its own using the Railway database setup I wouldn't expect to have to add more configuration to the container and if I did need to why wouldnt the popup that I saw when starting the process note this somewhere?

I am just not following why I would expect downtime for a migration for something in the settings I thought this kind of stuff would happen in the background and would at least tell me if I needed to update something.

I read the docs you posted but I am having trouble understanding how this is applicable to my scenario. Am I using the wrong access pattern? This is what my app has been running on just wanted it in another region.

When you change the region of a database, we move the volume from the current region to the region you choose.

This requires downtime because the data has to be physically moved from one region to another.

When you say you're able to access the database in the dashboard (through the Data tab) but is unable to connect externally, that hints at an issue with the connection details you're using. Could you confirm if you're using the right connection string/credentials for those connections?