I've recently been testing using the F button to start and stop the RPi when connected via the USB Power supply.

When I press the F button, the UPS correctly triggers shutdown, and the red LED on the pi as well as the solid SYS LED on the UPS are on. However, after the FFSD timeout (30s) the UPS enters LPR mode (SYS LED goes Off), and as soon as it does, the RPi reboots with the UPS still in LPR mode (no LEDs on).

If I just leave it, the RPi will happily work, but with no UPS functionality.

If I press the F button at this time, it hard resets the RPi and reboots it with the UPS working correctly again.

I have a couple of other hats on the RPi board. I am wondering if their power draw in LPR mode is somehow confusing the UPS and triggering a restart? or is the just he RPi?

Could you please help?

Thanks