Here is the solution. First you got to convert the clip into a new audio clip at the audio menu. Then it works. Here is my german review:
This is not how it should work or how we expect it. And at DOP you can’t move a lot of plugins at the same it. And it’s sad, that favorites are always added at the last plugin. Perhaps you want to add it before the last plugin, before the compressor. Some things are not well developed.