fix initial grid state

synth_engine.cpp

@@ -348,6 +348,10 @@ void SynthEngine::rebuildProcessingOrder() {
     rebuildProcessingOrder_locked();
 }
 
+void SynthEngine::updateGraph() {
+    rebuildProcessingOrder_locked();
+}
+
 float SynthEngine::processGridStep() {
 
     auto isConnected = [&](int tx, int ty, int from_x, int from_y) -> bool {