Hi all,
first of all: a big thank you to the maintainers of iodéOS, I love the concept and didn’t hesitate to flash once I got my ‘new’ Mi9 a few months ago.
I started off with unlocking the bootloader and flashing 4.9 with fastboot. At first glance it seemed to work really well but it has a super annoying issue which has been present for me in all versions until the current 4.15 release:
The device crashes / locks up regularly. Sometimes once a day, sometimes multiple times within one hour. When it happens, the UI gradually breaks in an almost creepy way: sometimes the navigation buttons disappear, sometimes the system bar becomes unresponsive, sometimes buttons within an app cease to work, … Usually during that phase, switching between already-running apps still works, but starting a new app will end up in a blank screen without the app ever being started. Within a few seconds, the situation gets worse until eventually the UI is entirely unresponsive, followed by a solid black screen.
Whenever the issue occurs, it is also impossible to properly reboot the device. Even if it’s still responsive enough to show the reboot menu, it will just endlessly show the ‘Rebooting…’ animation without ever rebooting.
So all I can do in that situation is a hard reset (pressing power button for ~10s). After that everything is back to normal until it starts falling apart again. Sometimes after a day, sometimes after 10 minutes. It sometimes also happens without any UI interaction. i.e. I pull the phone out of my pocket only to find it completely unresponsive (albeit still powered on).
Debugging the issue is quite difficult because the device doesn’t accept adb connections either when the problem occurs.
Some further investigations and analysis:
- It never reboots itself, so it’s most likely not a kernel issue
- It feels like when the “degradation cycle” begins the system becomes incapable of spawning threads/processes (not starting new apps, refuses to reboot, not accepting adb connections, …). Maybe the final black screen is some sort of watchdog trying to restart Trebuchet. It’s reminiscent of a Linux machine with a full root fs.
- It has never happened during the night when the phone is in airplane mode. So it could be somehow related to connectivity/networking
- Sometimes before the UI starts do disintegrate there seems to be a period of several minutes (or maybe even hours?) where the phone seemingly runs normal but silently looses all connectivity: Spotify says it’s offline, Push messages are not arriving (with Wifi/4G still connected)
These networking related observations make me wonder if the issue could be related to the iodé App?
Any help or debugging support would be greatly appreciated! I’m pretty much stumped with this 
(n.b. since the 4.12 or 4.13 OTA update, the iodé App does not really work anymore for me. It just won’t detect any app traffic and therefore also does not block ads and trackers anymore. That’s a pity but I assume it’s unrelated to the issue I’m describing here. The app used to work beautifully in the previous versions but the crashing issue happened in these versions already, so it’s unlikely to be related)