Re: easy solution: Replace that crap by a clean custom-ROM
"The article indicates the problem is with Xiaomi's firmware, which would not necessarily be affected by the installation of a custom ROM. "
I unfortunately bought a Xiaomi Note 8 and after only 3 months or so ended up rooting it and putting on a custom Rom. The amount of phoning home is non stop.
I also installed AFWall+ to stop parts of the Linux kernel and the Android system plus others from accessing the internet/data even though not allowed.......