Currently we cannot playback Widevine encoded multi-key rotation content on Roku devices.
Roku devices (Streaming Stick +) are making license requests for the all keys when attempting to play multi-key content. However the Roku fails to playback the Widevine content, On screen error: "Can't select chunk on any bitrate." and On screen error: "Decrypt Method not found." for Widevine Dash specifically packaged content.