Username in connection string is overridden by host IP address

I am trying to connect to an Azure MariaDB instance and seem to have my UID overridden by my local IP address. It appears from the docs here that I need to connect to my Azure MariaDB instance using the hostname of the instance.

Site runs on Docker-hosted MariaDB instance with no issues. The only delta here is the hosted Azure MariaDB instance.

    "Data": {
        "ActivityDb": "Server=MYDBHOST.mariadb.database.azure.com;Port=3306;Database=activity;Uid=delirium@MYDBHOST;Pwd=#NOT_THAT_STUPID;SslMode=Preferred;",
        "ApplicationDb": "Data Source=file:Application.db",
        "CustomerDb": "Data Source=file:Customers.db",
        "ReservationDb": "Data Source=file:Reservations.db"
    }

error:

"Error","properties":{
  "Exception":"MySql.Data.MySqlClient.MySqlException (0x80004005):
   Access denied for user 'delirium'@'#HOSTIP_REMOVED (using password: YES)\n   
   at MySqlConnector.Core.ServerSession.SwitchAuthenticationAsync(ConnectionSettings cs, PayloadData payload, IOBehavior ioBehavior, CancellationToken cancellationToken) in C:\\projects\\mysqlconnector\\src\\MySqlConnector\\Core\\ServerSession.cs:line 459   
   at MySqlConnector.Core.ServerSession.ConnectAsync(ConnectionSettings cs, ILoadBalancer loadBalancer, IOBehavior ioBehavior, CancellationToken cancellationToken) in C:\\projects\\mysqlconnector\\src\\MySqlConnector\\Core\\ServerSession.cs:line 361
   at MySql.Data.MySqlClient.MySqlConnection.CreateSessionAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in C:\\projects\\mysqlconnector\\src\\MySqlConnector\\MySql.Data.MySqlClient\\MySqlConnection.cs:line 442
   at MySql.Data.MySqlClient.MySqlConnection.OpenAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in C:\\projects\\mysqlconnector\\src\\MySqlConnector\\MySql.Data.MySqlClient\\MySqlConnection.cs:line 175
   at MySql.Data.MySqlClient.MySqlConnection.Open() in C:\\projects\\mysqlconnector\\src\\MySqlConnector\\MySql.Data.MySqlClient\\MySqlConnection.cs:line 161
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected)","server":"deliriumdb.mariadb.database.azure.com","DeveloperMode":"true","CategoryName":"Microsoft.EntityFrameworkCore.Database.Connection","AspNetCoreEnvironment":"Development","{OriginalFormat}":"An error occurred using the connection to database '{database}' on server '{server}'."}}}}

It works great connecting to a self-hosted MariaDB instance, this seems to be something with the connection string in Azure being overridden given that MySQL Explorer works fine with the credentials.

Am I missing something basic, or is this a weird Azure problem due to the hosted DB name?