i still think this is related to power as no crash log is seen
Have you monitored the input voltage and see if there is sudden drop on it when problem happens?
I have tried running it with a DC-DC buck converter that is guaranteeing 5vdc and I do see a drop in power draw when the device crashes. The voltage is constant but the current draw drops to nearly nothing .01-.03a Not sure of the margin of error on my measuring device but that is really low.