I was having the same problem earlier today, but it just started downloading now.

I found the issue (sort of). kmutil is launching com.apple.fsplaceholder, so I feel better that it is an Apple thing. I still don't know what is going on, but an example capture of one of the processes is shown below if anyone is interested. launchd forks, then executes xpcproxy with the arguments (xpcproxy com.apple.applefsplaceholder), and then executes kmutil with the arguments (load -b com.apple.fsplaceholder). 														 pid: 26919 									first observed: 2020-11-17 13:54:20 									 last observed: 2020-11-17 13:54:20 												 program: kmutil 										program path: /usr/bin/kmutil 											signing ID: com.apple.kmutil 												 team ID: 			 program modification date: 2020-01-01 00:00:00 						 program status date: 2020-01-01 00:00:00 														ppid: 1 									parent program: launchd 						 parent program path: /sbin/launchd 							 parent signing ID: com.apple.xpc.launchd 									parent team ID: parent program modification date: 2020-01-01 00:00:00 			parent program status date: 2020-01-01 00:00:00 FORK	/sbin/launchd EXEC	/usr/libexec/xpcproxy arguments: xpcproxy com.apple.applefsplaceholder EXEC	/usr/bin/kmutil arguments: /usr/bin/kmutil load -b com.apple.fsplaceholder exit	

No 3rd party kexts installed.

I took a cue from this old threadhttps://forums.developer.apple.com/thread/80337and built a very simplified UIViewController with an ARView and repeatedly went back and forth loading and unloading the view and displaying my somewhat complex model.Everything worked fine, so the problem in my larger program is clearly mine. I suspect my code is complex enough that I have one or more accidental retain cycles going on.I am going to close this thread.

A quick update.I have found that if in the ViewController with my ARView I override viewWillDisappear(_ animated: Bool) and remove the anchors added to the scene before the scene disappears, then the meshes do drop back down to normal when I reload the ViewControllerE.g.,self.arView.scene.removeAnchor(self.worldAnchor!)where worldAnchor is the root anchor for most of my content.HOWEVER, eventually FPS does drop even though the mesh count is low again. That is, the more times I reload the ViewController with the ARView, the slower the FPS becomes.So I still don't know how to correct for that.