This iterator should count down, not up

src/layers.cpp

@@ -122,7 +122,7 @@ Layer_::updateActiveLayers(void) {
 void Layer_::updateHighestLayer(void) {
   // If layer_count is set, start there, otherwise search from the
   // highest possible layer for the top active layer
-  for (int8_t i = (layer_count - 1); i > defaultLayer; i++) {
+  for (int8_t i = (layer_count - 1); i > defaultLayer; i--) {
     if (bitRead(LayerState, i)) {
       highestLayer = i;
       return;