Thanks for the offer, really appreciated. See Sponsors - Klipper documentation. Donation goes to @koconnor who is the lead developer of Klipper
From your log:
Timeout with MCU 'mcu' (eventtime=648.608440)
Transition to shutdown state: Lost communication with MCU 'mcu'
then followed by:
b'Got EOF when reading from device'
Unfortunately these kind of errors are hard to diagnose since there is not a single reason like BRLTTY or wrong permissions.
See Timeout with MCU / Lost communication with MCU for some hints.
You can also run sudo dmesg -ew
(this will give you a permanent “monitoring” output). Then provoke the error and check if there are USB related topics in the output.
This is not a Klipper error but an error between your printer board and the Linux host. Klipper is just reporting it. Unfortunately these ch341 UART chips are a major pain in the lower back and known to be problematic.