I just tried out Chromaphone 3.1.0 VST/VST3/AU on macOS Catalina in the AudioPluginHost and the editor displayed correctly for me. To investigate further, it would be useful to know the following:
Which plugins have you tested? Which ones cause problems?
What platform are you running on?
Do you see the same issue in the AudioPluginHost, or do things work properly there?
Without being able to reproduce the issue and debug it, it’s difficult to say why your workaround makes the editor appear.