samba3.x & members of groups defined with scope 'domain local' in AD, getting NT_STATUS_ACCESS_DENIED

Issue

AD users, members of groups defined with scope 'domain local' in AD, getting NT_STATUS_ACCESS_DENIED even if the correct AD group is configured under the "valid users" parameter
If the infrastructure combines both 2012AD and AD of previous releases, this only occurs when the 2012 DC is used as KDC by the clients

[2016/08/05 14:44:11.239420, 10, pid=4644] passdb/lookup_sid.c:76(lookup_name)
  lookup_name: DOMAIN\ADgroup => domain=[DOMAIN], name=[ADGroup]
[2016/08/05 14:44:11.239445, 10, pid=4644] passdb/lookup_sid.c:77(lookup_name)
  lookup_name: flags = 0x077
[2016/08/05 14:44:11.239854, 10, pid=4644] smbd/share_access.c:219(user_ok_token)
  User 'DOMAIN/ADuser' not in 'valid users'
[2016/08/05 14:44:11.239884,  2, pid=4644] smbd/service.c:627(create_connection_session_info)
  user 'DOMAIN/ADuser' (from session setup) not permitted to access this share (Samba_Share)
[2016/08/05 14:44:11.239910,  1, pid=4644] smbd/service.c:805(make_connection_snum)
  create_connection_session_info failed: NT_STATUS_ACCESS_DENIED