For this phone bug report must be on china forum not on global en.miui.com because its china phone not global.
To fix the problem and fix it, it is not enough to report a bug. To get something started, you need a huge number of confirmations from other users. And, in addition, you have to add the description of the problem, screenshots of the error, logs like for example: bugreport.zip, modem log, AP log, screens from dumb etc.
I dont know what to give you, since you do not want to help solve problems on this phone and additionally lied to other people writing that there are no bugs on rom 8.5.4.0 and you are hurt because the problem will be, and why fix it, after all it is not The problem is, it's a phone under china mobile ...
The same bugs report does not give you the fix to confirm this very large number of people and need to add logs. Writing everything works, you are cheating everyone and hence the problems that all will have until the death of this phone. I know exactly what the phone market is, but with such an approach as yours, no bug will be fixed. You write that everything works in 8.5.4.0 that is, you are lying to all, I'm not surprised that so many bugs since a long time, since users have an approach like yours. You do not really understand when reporting bug something gives and when not.
I write this guides:
http://en.miui.com/forum.php?mod=viewthread&tid=954138
http://en.miui.com/thread-1058687-1-1.html
Anyone from this forum read this and do example logs and add to bugreported threads? No one do that...
Okay, you are happy with the rom 8.5.4.0 it's up to him to stay, but do not write nonsense that there everything works, because it's not true.
This thread have in names word bus etc, and You dont write about any bugs, than dont write in this thread..