pixel 6a
release: 2023090600
after lastest update grapheneos automatically powers itself off after asking for sim pin then boots again in recovery mode with options to try again or factory reset
after more tinkering it seems that if sim pin is typed almost immediately phone will proceed to showing the lockscreen and boot normally from there on. if there is a short delay of about 4 seconds and more before entering sim pin phone will reboot in recovery mode even after successfully proceeding to lock screen. also, phone will reboot to recovery mode if presented with pin screen and no pin entered.
thank you for your time and effort looking into this