Debugging kernel: (AppleSMC) Previous shutdown cause: 3

Hey All - I am trying to run a OCLP late 2010 MBA running Monterey as a low power server.

The system is plugged in and running Amphetamine. I remote control use Chrome Remote Desktop.

Unfortunately, the system shuts itself down 3-8 days after boot. When I check the logs using

log show --predicate 'eventMessage contains "Previous shutdown cause"'

I see the following most often:

kernel: (AppleSMC) Previous shutdown cause: 3

Looking that up here, the system thinks I'm pushing the power button. Looking online, I see the following suggested fixes:

1. Reset the SMC and PRAM
2. Check thermals
3. Run a hardware diagnostic

I've done (1) and (2). No dice. The system runs in a ventilated cabinet that has other hardware in it as well that have no issue.

I'd do (3), but Apple's hardware diagnostic doesn't play well with OCLP.

I tried searching reddit for other's having this issue, but couldn't find anything OCLP specific nor anything over what I listed above.

So ... I'm stuck.

Any guidance from this group on what I can do?