Thanks for the instructions James, my issue was solved. The Tool "Lingon X" turned out to be the cause. It had a checkbox "Run at startup and when saving" that needed to be checked apparently. The viscosity helper was installed properly, but Lingon X interfered with launching it ...

Fresh install on macOS 13.0.1 (Viscosity 1.10.4). I got the prompt to install the helper tool. After installing it the app doesn't open unfortunately: "Viscosity was unable to install its helper tool and must now quit. Please reopen...". I uninstalled Viscosity with the instructions from a...