I was unable to turn off Graphene OS despite being in the main profile and being unlocked and pressing the on-screen button within the OS to power down the phone.
I tried many times and eventually had to hold down the physical power.
When I held down the power, it was still very hard to do this. It felt like I held it around 30 seconds and eventually my hand slipped, then I had to do it again. The power button is small and it's not easy to keep it held down that long.
Eventually it rebooted.
I have never had this happen before but it seems like a possible security issue because being able to go into fully locked mode quickly could be important.
I am in a country with many laws and although I am trying to not break them, there are so many and many of them are ambiguous. In the absence of certainty of how laws will be interpreted and without the ability to remember all laws at all times and with my distrust of authorities, It is safer for me to power off or shutdown my phone if I think it could be searched, but if the risk of being searched is low (but greater than 0) then I would rather not use the duress pin.
I also don't know if the duress pin would have worked since I didn't want to lose my data and it didn't happen when I was at immediate risk of a search. I am concerned this may have been a targeted attack that affected me.
I do not have another phone but probably should use the App used to verify the device integrity and do not know if I can run this using KVM simulation and attaching the phone via USB to a laptop and a KVM virtualization of waydroid.
There was no reason the device shouldn't have been able to shut down. It's new and completely up to date. This was either an error in the software or a 0day or some sort of App affected the operating system from running correctly. I tried to shut it down many times the normal way, as I have done before. This was not error by the user.