Hi,
Just to be clear, copying a compressor that is working normally in another channel, fails to pass or meter a signal in the problem channel’s signal path. When removed, the signal path is restored?
Can you move your project or .cpr file to another system and see if it works there? At least then you can determine whether it is an issue with your Cubase program, or is specific to individual projects. If you’re unable to do that pm me and we’ll arrange something
I agree with G-string, first, move to the latest possible update of your Cubase version
I do know that certain systems can throw up odd behaviours, on mine for example, the Cubase chorus plug causes distortion right across all my audio!! All other plugins behave perfectly!
Good luck, let us know what your testing reveals.
P.