From the above linked pdf, it should be noted that
"In this work we study the Chinese version of the Android OS distributions run by Xiaomi, Realme, and OnePlus handsets. We measure the network traffic the handsets generate when in-use by a
privacy-aware consumer. We find that these devices come bundled with a number of third-party applications, some of which are
granted dangerous runtime permissions by default without user
consent, and transmit traffic containing a broad range of geolocation, user-profile and social relationships PII to both phone vendors
and third-party domains, without notifying the user or offering the
choice to opt-out. In contrast, the data shared by the Global version
of the firmware is mostly limited to device-specific information.
Our study therefore highlights major differences in terms of how
privacy provisions are enforced in different regions."
In addition the study is dated 2017 and concerns Android 11. All the same, a disturbing portrait of mobile phone "security". Seems a mobile phone can be your best friend or your worst enemy.