Python Custom Widgets in Qt Designer

[WolleKette]

Hi at all
some times ago, I dealt with how to write own widgets for the pyside6-designer in python. And I was able to do that for my purpose at the time. Thanks to the tutorial under Using .ui files from Designer or QtCreator with QUiLoader and pyside6-uic. I also tried some examples like the Wiggly Example from the qt documentation.

Now to my question:
Today, I use virtual environments for python and my custom widgets appears only in the pyside6-designer when I'm in the corresponding project. Depending on the PYSIDE_DESIGNER_PLUGINS Variable.
But! The sample widgets from my earlier attempts are always loaded in the designer. No matter in which project I am.

I have no idea how this works and how to get rid of those plugins.
Can anyone give me a tip. (I work. under MacOS).

Thanks in advance