

That must be Xiaomi’s fault… Android does not do such thing. Check the running processes in Developer Settings to see what’s running that could cause this. After located, disable/uninstall them, with ADB if needed.
Live wallpapers are often a form of ads. Like Motorola have Live Lockscreen, made and owned by Taboola… This is why you should skip bloated Android devices, unless you use a custom rom or don’t mind the extreme debloating.
Is the software buggy? I did not like the Fairphone 5 mainly because of how buggy the Google Android version was… I had random reboots and freezes, framerate issues, UI elements that glitched or didn’t fit the screen properly. Hope they were able to fix that by now.
I too have the Gen 6, but i choose the e/OS version. Great phone so far.