[LAU] MIDI automation in Carla not working? Audio Gain and others

Hi, I try to setup a Carla live performance host. My instruments are working fine but I want to use a pedal to control the overall volume of audio output. I connected all synth outputs to the audio gain plugin from falktx (but tried with other plugins as well) and the MIDI output of the keyboard to Gain Control's events-in. So far I was not able to get this plugin MIDI controlled. I don't need MIDI learn but I like to adjust the gain by any cc controller message. I might do something wrong or it is not working. Before I do a bug report I wanted to ask the list if midi control of internal plugins is working for you? In the videos of falktx it seems to work. I am using version 2.6.0-alpha1. Older bug reports mention the problem thus others seem to be hit by the same problem?! So far I use JackMix as an external jack application but it would be much more convenient to use an internal plugin. IMHO controlling plugins by MIDI CC messages is an essential feature of a plugin host. thank you for your time Gerhard