Bug in the speaker phone for redmi note 4X. Repeatability 100% sound goes through perfect for the listener but when sound goes out there's loads of reverberating sounds for the speaker.
They aren't going to put out an Android 7 build for mtk. They can't even fix the battery drain/battery bugs. :-( I will give another manufacturer my business next time. And for sure I won't do mtk based devices again...