SqlDependency Works with local DB but not with servers - sql-server

Question

using this code:
private async Task<object> ChatNotification()
{
try
{
string cs =dbConnectionStr;
using (SqlConnection con = new SqlConnection(cs))
{
con.Open();
string cmdText = #"SELECT
[dbo].[ChatMessage].[Id],
[dbo].[ChatMessage].[fkUserId],
[dbo].[ChatMessage].[fkGroupId],
[dbo].[ChatMessage].[Message],
[dbo].[ChatMessage].[DateTime],
[dbo].[ChatMessage].[IPAddress]
FROM [dbo].[ChatMessage] ";
SqlClientPermission permission =
new SqlClientPermission(
PermissionState.Unrestricted);
try
{
permission.Demand();
}
catch (System.Exception ex)
{
}
using (SqlCommand cmd = new SqlCommand(cmdText, con))
{
cmd.Notification = null;
SqlDependency tradeInfoDependency = new SqlDependency(cmd);
tradeInfoDependency.OnChange += DependencyNotify_OnChange;
if (con.State == ConnectionState.Closed)
{
con.Open();
}
SqlDataReader reader = cmd.ExecuteReader();
}
}
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
return Ok( );
}
//dependency******
private async void DependencyNotify_OnChange(object sender, SqlNotificationEventArgs e)
{
ChatNotification().Wait();
var dependency = sender as SqlDependency;
if (dependency == null) return;
if (e.Info == SqlNotificationInfo.Insert || e.Info == SqlNotificationInfo.Merge)
{
var chats = _dbContext.ChatMessage.FromSql(#"SELECT * FROM [dbo].[ChatMessage] " +
"WHERE IsSeenByAdmin=0").OrderBy(c => c.DateTime).ToList();
dependency.OnChange -= DependencyNotify_OnChange;
await _chatAdminHubContext.Clients.All.SendAsync("AdminListen",
chats);
}
}
public Startup(IConfiguration configuration)
{
SqlDependency.Start(dbConnectionStr);
Configuration = configuration;
}
the whole thing works with this connection string which is connected to my localdb:
private readonly string dbConnectionStr=
"Data Source=.;Initial Catalog=signalr;Integrated Security=True;user id=sa;password=******";
but it does not work if i change the connection string to this:
private readonly string dbConnectionStr=
"Data Source=server.*****.com\\MAININSTANCE;Initial Catalog=signalr;Persist Security Info=True;User ID=sa;Password=********";
i can connect to the server and local db with no problem, and can use fetching data with entityframework from both, the connection is made successfully yet the only problem is that when i insert row in localdb [dbo].[ChatMessage], dependency works but when i insert row in servers [dbo].[ChatMessage], it does not.
the only thing i did was to set broker enabled. Could it be related to any permissions on server's db?
UPDATE:
select * from sys.transmission_queue
gives this transmission_status:
An exception occurred while enqueueing a message in the target queue. Error: 15517, State: 1. Cannot execute as the database principal because the principal "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission. 5