This bug occurs day to day while the phone is sitting on the table.
Its frequent, random and [my theory...] may be triggerd by Bluetooth signals and/or app permissions.
Upgrade to MIUI 12.0 did not solve it.
Also been posted on Reddit.
'Google Play Services has stopped' message
Mi5 MIUI 8.2.1.0 Android 7.0 NRD90M
Did factory reset.
Followed all the tutorials on MIUI forum.
Google apps install OK
BUT Google Play Store just hung on install.
So...
Downloaded GPServices 10.2.99 from APKmirror.com
Downloaded GPStore 7.6.08...