HDRP does not support separate directional light cascade atlas caches for each cameras which can be updated separately when the shadow update mode is set to OnDemand. A single atlas is used for all cameras with the consequence that cameras which have no shadow casters (for instance because they are filtered out with culling masks) may invalidate the shadow maps of other cameras. In the use case described in this ticket, disabling the GPU Resident Drawer actually displays a behavior that seems to be working because the way the SRP batcher handles culling compared to the GPU Resident Drawer. In this case, when the other camera doesn't need shadow casters, users should disable shadow mapping entirely for that camera by enabling Custom Frame Settings in the Camera component, enabling the Shadow Maps override in the Lighting section of the frame settings and disabling Shadow Maps (see https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@17.0/manual/frame-settings-reference.html#lighting).