Reproduction steps:
1) Open user's attached project
2) Open "Pond" scene (located in Assets/DepthBug/Demo/Scenes)
3) Change "Rendering Path" to "Deffered" in Edit > Project Settings > Player > Other Settings and make sure that "Graphics APIs for Windows" is set to any except "Direct3D9"
4) Notice how "Water" game object looks like
5) Change "Graphics APIs for Windows" to "Direct3D9" in Edit > Project Settings > Player > Other Settings
6) Notice how "Water" game object looks like now

Expected result:
"Water" with "Graphics APIs for Windows" set to "Direct3D9" should be rendered same way as "Graphics APIs for Windows" to "Direct3D11" or any other

Actual result:
"Water" with "Graphics APIs for Windows" set to "Direct3D9" has visual glitches

Note:
When "Rendering Path" set to "Forward", everything renders as supposed to.

Note 2:
When "Rendering Path" set to "Legacy Deffered (light prepass)" issue also reproduces.