Unity is working on something, but on what?

Hello guys!

I am working with the Editor script and have a quite complex structure, containing different gameObjects. Before I start some tasks through a separate thread, before that - I am storing different Scripts on those gameObjects into a single list. I call this process "ScriptBaking". That includes using GetComponent for many of those objects at once 200+. It's unavoidable, since I need to store a reference to those script instances, but it's not the problem.

Keep in mind that all of this is happening in the Editor script. I display a progress bar as I am working through the bake process.

This bake process is of course not threaded. It goes well, and takes about 4 seconds to go through all the game objects, I get a nice reference to the scripts. It's okay if I do it again and again, until somewhere at 4th bake - the progress bar starts to really turtle somewhere from 70%. 5th time it will turtle at 60% and so on.

Moreover, I can see that unity is still doing something in the Mac menu. Please have a look at the picture. The progress circle makes a full turn, then starts again?

after some time (4-5 minutes after 5 re-bakes) the progress circle, or pie on the thumbnail hides after several laps. "Bake" is fine once again.

WTF is happening? :D Is it an automatic clean-up some sort? How is the progress circle tied with the turtling of "Baking"?

here is the function, gets invoked on button click from OnInspectorGUI( )

//the variables declared and initialized on the top of the editor script

 NodeCounter _nodeCounterShort = GameObject.Find("mainNodeCounter").GetComponent<NodeCounter>();
 //Node Counter contains the list of all gameObjects in the scene, "the nodes.
 
 void BakeNS(){
         
         float counter = 1; //used to display progress
 
         foreach(GameObject g in _nodeCounterShort._AllNodesInScene){
             
             NodeSpark _dump = g.GetComponent<NodeSpark>();
             _dump._NSneighbour.Clear(  );
             
             
             foreach(GameObject gg in _dump.neighbours){
                 _dump._NSneighbour.Add(gg.GetComponent<NodeSpark>());
             }
             
             EditorUtility.DisplayProgressBar("saving the NodeSparks of neighbours for every node", counter + "/" + _nodeCounterShort._AllNodesInScene.Count, counter/_nodeCounterShort._AllNodesInScene.Count);
             
             counter++;
         }
         
     }//end of BakeNS()