Pharmonie, your case is a little different because you use the free version in which case you should use the special version available at
https://www.sweethome3d.com/downloads/SweetHome3D-6.6-macosx-jogl-2.3.2.dmg
As this version can't be notarized, you'll have to launch it the first time by ...

I had a similar problem. So far, unfortunately, I could not find a solution.