gilded siren
there are two instances in your log where klipper is unable to communicate with an MCU as it's shut down. it appears to be the main MCU i.e. the manta.
as far as i can tell it seems to be happening during the setup phase of klipper running.
on any other mainboard/sbc combo i'd tell you to check the USB connection between the two devices but that's not applicable here.
it would lead me to wonder about your wiring, power supply etc. i note from your config you're also running a klipper expander. are you perhaps asking too much of a power supply?
vale dust