Steps to reproduce:

1. Open attached project "AssetBundleBuildScene.zip"
2. Open build settings and set build mode to developement with "Autoconnect profiler" enabled
3. Build and run project
4. In profiler, grab snapshot of detailed memory. Under "Not Saved" inspect Materials and RenderTexture
5. Get back to built exe and change scene by clicking left mouse button
6. Get back to profiler and grab another snapshot
7. Notice that number of materials is increased although scenes are identical. Also, although scene two is loaded, there are reflection probes that reference the first scene

Note: On each scene change, number of materials is increased and after a number of scene changes there can accumulate as many as 100 of them

Reproduced with: 5.4.0b14, 5.4.0b18