I had basicly the same issue, tacking worked fine but was unable to set channel or enable power saving
Solved it by
1.lauch steam as admin (may not be needed)
2.uninstall steamVR from tools
3.Delete the steam VR folder from documents and Steam install folder/appdata/common
4.Restart PC (may not be needed)
5.Reinstall steamVR
This solved it for me even checked after reboot etc