samba - Aug 2016 - ADUC can manage group membership but samba-tool failed

hi:
    I got an account whose group membership can not be managed via
samba-tool. the procedure below:

[root at dc ~]# /usr/local/samba/bin/samba-tool group listmembers test_t105011
t105011

[root at dc ~]# /usr/local/samba/bin/samba-tool group removemembers
test_t105011 t105011
ERROR(exception): Failed to remove members "t105011" from group
"test_t105011" - Unable to find "t105011". Operation
cancelled.
  File
"/usr/local/samba/lib64/python2.7/site-packages/samba/netcmd/group.py",
line 278, in run
    add_members_operation=False)
  File
"/usr/local/samba/lib64/python2.7/site-packages/samba/samdb.py",
line 274, in add_remove_group_members
    raise Exception('Unable to find "%s". Operation
cancelled.' % member)

but I can add/remove group membership via ADUC for this account. other
accounts are good via samba-tool/ADUC.

I don't know how to debug further for this situation. thanks a lot for
help and hint!

Regards,
tbskyd