Workaround: Explicitly disabling HDR in the Camera or in Project Settings->Graphics restores the original direct rendering behavior.

Root problem is that the depth buffer is not bound and blitted at the same time that the color buffer is bound when temporary color and depth buffers are created in the rendering pipeline.

Repro case is pretty easy:

1) Create a new 3D Project in Unity 2020.1
2) Add XR Plug-in Management 3.2.15 or later.
3) Add Windows MR XR Plug-in 3.3.1 or later.
4) In XR Plug-in management make sure that Windows Mixed Reality is enabled for Standalone.
5) In the sub settings for Windows Mixed Reality make sure that the Shared Depth Buffer setting it toggled on.
6) Go to the scene and place a cube so that there is something rendered. The closer to the camera the easier you will see it in the temporary buffer.
7) Enable Render Doc
8) Make sure that the Holographic Remoting app is running on the HLv2 device. The app will tell you what the IP address is to connect to.
9) Open up XR->Windows Holographic Remoting, enter the IP of the device to connect to and press Connect. Wait for the device state to be Connected.
10) Hit Play in the Editor.
11) When rendering is visible, select the Render Doc/Camera button to capture the scene.