There appear to be several issues with the project. First of all, when a "Load" action is expected (which appears to be the case based on the forum thread), the Render Graph needs to be told we still need the texture contents. This is done by specifying read access in addition to write access, using AccessFlags.ReadWrite.
We also suggest using renderGraph.AddBlitPass to blit using Render Graph https://docs.unity3d.com/Packages/com.unity.render-pipelines.core@17.0/api/UnityEngine.Rendering.RenderGraphModule.Util.RenderGraphUtils.html