I've started to get it in the last month or so. It seems to happen after one of it's random reboots (once or twice a week). I'll check ring sound and find it's been turned off. I simply slide the volume back up again.

Another customer complaint on this fault: "The phone just goes into a state where it does not receive calls and people can't ring me. Service doesn't come back until I restart the phone" I've just experience that as well. The phone didn't like going down in the London underground and comi...

Which button is 'Menu'? http://www.kylook.com/en/faq/android-where-is-the-menu-button/ Unfortunately, that's not specific to the BV500 (but I have tried long pressing all those buttons already-with no joy) The user manual: https://fccid.io/2APMJBV9500/User-Manual/User-Manual-3996038 is of no help a...

Which button is 'Menu'?

I'm down to about one random reboot a week now

I solved the slow charging problem by swapping to a new cable. Fast charges now

I too have noticed that. Sometimes it happens when when you take the phone off silent mode.

By checking the app you mentioned (Wim Hof Method) at the Play Store, noticed this (in the app information paragraph): NOTE: The Extended Pack performs unpredictably on certain devices, including those made by Huawei, OnePlus and Blackview. This is due to their proprietary operating software. The p...

Thanks for that info/link.......I'm still leery about doing it though

Is your phone rooted? If not, could you explain how you got to system/usr/keymap/mtk-kpd.kl on the phone please?
edit.....just seen your post in the "root" thread so I'm assuming you've rooted your phone to be able to do that