[wrxtasy]

@wrxtasy I got the box working again in downgrading to Android 6 MM. Used the Vietnamese guide (http://daivietpda.com/2017/11/mdz-16-abh...-0-to-6-0/) that worked very well. So the system part was obviously ok, since you have to backup it and restore it again after the flash back to Android 6. After that everything worked again. 

Good news them

But I have some other questions you might help me with please. First of all I have SPMC 17 beta running on my box. Everything is back to choppy obviously. I´m just a bit confused with the settings of the box. First of all, there´s "Automatic Display adjustment", "HDMI self adaptation" and finally "optimize for resolution/framerate" in the developer settings. So quite a lot of settings for nothing ?

- HDMI Self adaptation (aka AMLogic Frame Rate Automation) only works with Amcodec Hardware acceleration.
- With SPMC 17.x Amcodec Hardware acceleration must be OFF - otherwise expect video sync problems.

- user-debug Firmware is needed for Root access on the Mi Box - "once" is not going to do it. That is why chmod is not working.

In the end you should buy a AML S9xx box and run LibreELEC Kodi Krypton on it if you want perfectly smooth, reliable video playback with AMlogic hardware. The Mi Box is not going to cut it for extra demanding Kodi usage which is what you are trying to do. Use it for non-Kodi Android TV Apps only.

If you want to view mixed SDR / HDR10 video content I would NOT use a NVIDIA Shield either due to it's colorspace problems. Otherwise you will be fiddling with Android settings continually again.