Raspberry changed, Teamviewer does'nt start anymore

Hello,

I had to change to a new Raspberry (3b+) board. The OS... Config is the same (same card).

Now the teamviewer host is no longer available. I found that is does'nt start automatically plus I cannot start it manually. I guess it has to do with the new mac adress, but how can I fix it?

If I have to reinstall teamviewer, what is the commandline to uninstall it?

Kind Regards for any hints!