I have same issue with CEC, before on older version of Coreelec was without problems, then every new update problems with CEC was stronger. Sometimes was enough when switched from HDMI to TV and oposite to wake up tv box by CEC remote. Now hawe to switch couple times to make it work. Another thing is problem with wifi, wan’t connect by wifi with router. My tv box is T95x2 (s905x2- coreelec 19.5 matrix).