It appears that when I have several nodes attached 10-12 or more I get back a bad eui64 when doing an "zcl global read 8 0" which executes emberLookupEui64byNodeID(). Its approximately 10% of the time. If I have fewer nodes all come back OK.
Could you share a packet trace to demonstrate the problem? I'd like to see the packet details and investigate more. If you don't want to share the trace in public, please feel free to provide it via the support portal.