How to reproduce:
1. Open the user's attached project
2. Open Assets > Scenes > SampleScene.unity
3. Enter Play Mode and press spacebar
4. Observe the Console window and the terrain in the Game view
5. The "Hidden/TerrainEngine/Details/WavingDoublePass (UnityEngine.Shader) is here" message is present in the Console window
6. Go to File > Build Settings and press Build And Run
7. Observe the terrain in the Player and press spacebar
8. Go to the Player.log and look for the "Hidden/TerrainEngine/Details/WavingDoublePass (UnityEngine.Shader) is here" message
Expected result: The WavingDoublePass shader isn't missing and AssetBundles built with older Unity versions should still work
Actual result: The WavingDoublePass shader is missing and the terrain is different
Reproducible with: 2021.2.0a1, 2021.3.5f1, 2022.1.8f1, 2022.2.0a18, 2023.1.0a1
Not reproducible with: 2019.4.40f1, 2020.3.36f1, 2021.1.28f1
Reproducible on: Windows 10
Notes:
1. The tested AssetBundle is built using Unity 2019.4.30f1
2. The WavingDoublePass shader seems to be replaced by “Legacy Shaders/Diffuse shader” in the Frame Debugger ("FrameDebugger_Player_ActualResult.png")