AD group added to SQL as sysadmin not allowing users to login who are part of the group

Question

So I am helping with some work and we have built a few servers in Azure with their SQL server image. Everything seems healthy apart from when adding an AD group for the domain admins to access SQL i get the following error below. I can add the users in individually however thats not very practical.

AD group is Universal and a security group however i did also try creating a global group but that did not work either.

Server is configures with SQL and Windows Auth and SQL is 15.0.4188.2

===================================

Cannot connect to W-P-SQL-VM-04.

===================================

Login failed for user '****\RS_Admin'. (.Net SqlClient Data Provider)

------------------------------ For help, click: https://learn.microsoft.com/sql/relational-databases/errors-events/mssqlserver-18456-database-engine-error

------------------------------ Server Name: W-P-SQL-VM-04 Error Number: 18456 Severity: 14 State: 1 Line Number: 65536

------------------------------ Program Location:

at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling, SqlAuthenticationProviderManager sqlAuthProviderManager) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions) at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource1 retry) at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) at System.Data.SqlClient.SqlConnection.Open() at Microsoft.SqlServer.Management.SqlStudio.Explorer.ObjectExplorerService.ValidateConnection(UIConnectionInfo ci, IServerType server) at Microsoft.SqlServer.Management.UI.ConnectionDlg.Connector.ConnectionThreadUser()

Answer 1

A very basic thing but when you say "AD", do you mean Azure AD (AAD) or on-prem AD? Azure SQL Database supports Azure AD, so if your group isn't available in AAD (e.g. it hasn't been synchronised from on-prem AD), that could be your problem.