Just upgraded a MiBox from 6.0 to version 1028 beta Nougat. Box connected to a Sony 1070 AVR which is connected to a Bravia. Worked fine under 6.0 - the Nougat beta however complains that it cannot display content due to lack of HDMI 2.2. Upgrade - automatic one - was done while connected so no cable change, no port change - one moment 6.0 and all working and next moment 7.0 and no go.
Direct connect to TV works however - but that's not what I'm after...
yes, same problem here with my denon, my rec is 4k hdcp 2.2 compatible on all ports, my tv is old panasonic viera 1080p plasma, and for some reason, new firmware does not negotiate hdcp 1.4 as it should, and as did before. Connecting to tv directly works fine but I loose 5.1 audio.. We're stuck now I'm afraid, no combination of software switches on mibox or receiver worked for me :/