No connection from Visual Studio to an Oracle database

Dear experts!

I am trying to get a connection from Visual Studio 2022 to an Oracle database. Unfortunately, I always get the message: ORA-12514: TNS: Listener cannot currently resolve the service specified in the connect descriptor. I've searched and tried a lot, but nothing works.

The configuration:

Imports Oracle.ManagedDataAccess.Client

Dim oradb As String = "Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=SVLHR.www.bkhl.at)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=LSAL)));User Id=xxx;Password=yyy;"

Dim conn As New OracleConnection(oradb)

        Try
            conn.Open()

...

The tnsping works:

H:\>tnsping svlhr.www.bkhl.at

TNS Ping Utility for 64-bit Windows: Version 19.0.0.0.0 - Production on 20-NOV-2021 14:36:03

Copyright (c) 1997, 2019, Oracle.  All rights reserved.

Parameterdateien verwendet:
C:\Oracle\product\19.3.0.0\dbhome_1\network\admin\sqlnet.ora

Adapter HOSTNAME zur Aufl÷sung des Alias verwendet
Verbindungsversuch mit (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=))(ADDRESS=(PROTOCOL=tcp)(HOST=172.16.4.185)(PORT=1521)))
OK (20 ms)

It's no problem to connect with Oracle SQL Developer. Oracle Client 19c is installed. PATH Variable includes PATH = C:\Oracle\product\19.3.0.0\dbhome_1\bin

The tnsnames.ora is set with the description, but i think i don't need the tnsnames.ora because i set the hole description in my connection string.

What options do i habe now? What can i try?

This is my first request in this forum. I hope I do it right. Thank you in advance for your help.

Jörg