I'm a pretty experienced Raspberry Pi / Raspian / Raspberry OS user and can't figure this one out.
Background: I started encountering this issue about a month ago on two varieties: RPi4 and RPiZero2. I have RPiZero, RPi3B+ but have not seen this behavior on them. This has happened on about 5 of my 12 Pis. They run fine for about 2-3 days and then start rebooting continuously. I run virtually the same load on all my Pis (Debian Bullseye Legacy Lite and apps loaded by Ansible). I have tried the newer 64-bit Raspian load but saw the same behavior.
Symptom: After reaching the console (autologin at boot), the system reboots after about 2-3 seconds. No warning. Reboot takes about 15 seconds and it never stops. I think this may have destroyed one RPi4 and one RPiZero2W all I get now is a solid red LED on the RPi4 and a solid green LED on the RPi02. I'm using libcamera and the Pi Camera Module v3 on the ones that are having an issue.
Debugging so far: I've checked my logs for low voltage warnings (none) before the system starts reboot-cycling, but I can't get the system to run long enough to do much debug after this begins.
Any clues on how to debug under these conditions are appreciated.