@unfa ah yes, because the canvas positions are saved in the json file, not the main carla project file.
it is an architecture/design problem. the plugin version has some state, but the UI is something that needs to be saved as well, even though the DSP/backend side has no use for it.
I can add a canvas->save-positions action, but having that automatic is tricky. we do not want to keep sending position data all the time, and we dont want to wait for UI stuff when saving host session. thoughts?