I’m so sorry.
RTFM…
I followed a post from BobRak with witch discribes that OH 3.1 is nessesary that autodiscover works witch smartthings again.
OH3 Smartthings Add-on Discovery not working - Development / Add-ons - openHAB Community
Within this post i seen that a specific SmartApp and Device Handler has to be deployed for the openhab integration with smartthings.
OpenHAB-Smartthings/SmartthingsInstallation.md at master · BobRak/OpenHAB-Smartthings · GitHub
After these steps autodiscovery works and my virtual switch works to.
Now i can control a variable throug my SmartTag. This is realy nice. Now longer using my Homematic remotes.
Thank you for your assistance.
Sascha