Please please please forgive me if I am wrong, but I took a look at the HDMI static protection circuit you have linked to and I think it is incorrect. I am using a similar device to the CM2020, in my case a TPD12S521. The devices uses mosfets as level shifters on the 4 control lines, CEC, SDA, SCL and HPD. On your circuit when the external Hotplug detect signal (HPD) goes high the internal level shifting mosfet will turn off. In your schematic there is no pull up resistor on the RPi side of the CM2020 to turn on the DMG1012T mosfet, Q5, so the gate will just float. I think you need a resistor to 3v3 here.
Also I think there is a problem with the CEC circuit. Again there is an internal level shifting mosfet between the CEC_IN and CEC_OUT pins. The gate of the internal mosfet is connected to the LV supply which is 3v3. You have then connected a second level shifting mosfet , Q4, in series and connected the gate up to 5v. I'm not clear what the effect of this will be but it does not look right to me. Seems to me like the Q4 is not required.
Once again please accept my apologies if i'm wrong, which I have been many times in the past