I am not sure, sorry man.
I just pushed an update, version 6.9, that closes the bank after everything is withdrawn before executing walking. It will also now say in the logger "Walk to combat" when the walking method is called, this should help me figure out what the root of the problem is. I still haven't had luck replicating the bug but when 6.9 goes live would you mind posting a copy of your logger when/if the issue occurs? This should help me determine if the problem is walking or banking related.