[LAU] jconvolver does not find a running Jack2 server

Hi everyone, in the last couple of weeks I started playing with jconvolver. (Thank you Fons!) First I tried it on OSX and it works quite nice there with some FIR I generated. When I tried the same on Manjaro I ran into a problem. I start the Jack server using Cadence (as I usually do), but when I try to start jconvolver in the terminal it returns a message that no Jack server is running. All other applications (ardour carla etc.) work fine. I tried to delete the Jack configuration files but that did not help I also tried to run jconvolver -s jackd / jconvolver -s jackdbus but also without success. I have run into a wall trying to find the cause of the problem. I would really appreciate if someone could point me in the right direction. Best regards Moshe