denox

Since you and other people are reporting similar problems, this is becoming a known issue, but we don't know what is causing this, nor we have a solution, except rolling back with a kernel.

To check what is available:
apt-cache policy linux-image-next-sunxi Install specific version:
apt install linux-image-next-sunxi=VERSION linux-dtb-next-sunxi=VERSION Do the same with u-boot: (check versions first, they might be different than kernel)
apt install linux-u-boot-bananapipro-next=VERSION  
In general, help out with this table: https://www.armbian.com/kernel/ and adjust board name appropriately.

Please do report back, how it went.

I'll keep monitoring my machine, without some services running, to see if it crashes again to try and isolate whether or not it is power (or peak) consumption related.
 
After the next crash I will also roll back the kernel and try again.