After the Windows update, I finally updated the MacOS versions of my preamplifiers. To register the Audio Unit v3, you just need to launch the app, which was the step I was missing.
Currently only the Windows version (VST3 32bits and 64bits) has been updated and is available on GitHub here for the bass preamp and here for the guitar preamp.
How do I get a Mac OS version of ATKBassPreamp?
Haven’t had time to create a MacOS release yet, it slipped my mind as I was working on fixing the workflow for Apple 😐
This is now fixed, I think I messed up the upload at the time.