I had this problem due to a 2 ways parameters change.
– The host was changing a parameter
– My effect got the change and updated a slider
– Next frame, the slider notified the host it was changed
– The host thought I just started a parameter gesture and then put the “back to arrangement” button on.
To solve, I just had to avoid the slider to propagate the change.
theSlider->setValue(aMainValue, dontSendNotification);