Report Server Windows Service (MSSQLSERVER) cannot connect to the report server

I have 2 SQL servers, 1 principal and 1 mirror on a remote site. On the mirrored server, the following error is being logged.

Report Server Windows Service (MSSQLSERVER) cannot connect to the report server database.

The application domain WindowsService_17 failed to initialize. Error: Microsoft.ReportingServices.Diagnostics.Utilities.ReportServerDatabaseUnavailableException: The report server cannot open a connection to the report server database. A connection to the database is required for all requests and processing. ---> System.Data.SqlClient.SqlException: Cannot open database "ReportServer" requested by the login. The login failed.

Login failed for user 'MYDOMAIN\sqladmin'.

at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)

at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)

at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)

at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)

at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject)

at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart)

at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)

at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)

at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)

at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)

at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)

at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)

at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)

at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)

at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)

at System.Data.SqlClient.SqlConnection.Open()

at Microsoft.ReportingServices.Library.ConnectionManager.OpenConnection()

--- End of inner exception stack trace ---

at Microsoft.ReportingServices.Library.ConnectionManager.OpenConnection()

at Microsoft.ReportingServices.Library.ConnectionManager.ConnectStorage()

at Microsoft.ReportingServices.Library.ServiceController.ServiceStartThread(Object firstStart).

TCP/IP and Named Pipes are enabled on both servers. When I open up the Report Server Configuration Manager on both servers, the settings match so I'm kind of lost as to what's causing this issue.

You can't connect to a mirrored database. It is not available for querying. Stop the process that is trying to connect to it so that this error is no longer logged. Start the process when you do a failover to the mirror server.

Or use readable secondaries in Availability Groups.

Or am I not understanding the question?