Disable experimental graphics jobs (this forces multithreaded rendering in 2018.3, which is a problem for the ARCore package)

ProjectSettings/ProjectSettings.asset

   useMacAppStoreValidation: 0
   macAppStoreCategory: public.app-category.games
   gpuSkinning: 1
-  graphicsJobs: 1
+  graphicsJobs: 0
   xboxPIXTextureCapture: 0
   xboxEnableAvatar: 0
   xboxEnableKinect: 0