Found an interesting article on the Graphene Android open-source OS and its device "not at rest" firmware exploit issues. This affects Google Pixel and Samsung Galaxy phones.
The Google response:
"GrapheneOS is a third-party mobile operating system based on the Android Open Source Project. GrapheneOS reported these issues to our Android Vulnerability Reward Program (VRP) on January 2. We are in the process of reviewing and determining next steps" - Google
https://www.bleepingcomputer.com/news/security/grapheneos-frequent-android-auto-reboots-block-firmware-exploits/