gnome-terminal - I have no name

Question

Environment:

• OS: Ubuntu 14.04.5 LTS x64
• HW: VM on vSphere with 2vCPU and 2GB Memory
• Default GNOME desktop installation with gnome-session-flashback 3.8.0.
• Connected to AD domain using Samba and winbind (see files below).

Issue:

Login etc. is successful, but when opening a gnome-terminal, sometimes there is I have no name!@hostname:~$ instead of username@hostname:~$

Facts:

• Can be easily reprocuded by opening e.g. 20 gnome-terminals (for i in {1..20}; do gnome-terminal; done)
• In the "failing" terminals, whoami reports the correct username and USER variable is set.
• Running the different commands (whoami, wbinfo -m, getent passwd username, id username) over a period of time (e.g. infinite for loop with sleep 1) does not return any failures.
• No errors found in samba / winbind logs.
• Configuration seems to be okay (otherwise it would always fail).
• Issue also exists on default GNOME environment

krb5.conf

[libdefaults]
 default_realm = MY.DOMAIN.COM
 dns_lookup_realm = false
 dns_lookup_kdc = false
 ticket_lifetime = 24h
 renew_lifetime = 7d
 forwardable = true

[realms]
 MY.DOMAIN.COM = {
  # KDC is the key distribution server
  # One per line in the format
  #kdc = ##adsrv##
  ##KDCSERVER##
   kdc = dc1.my.domain.com
   kdc = dc2.my.domain.com
   kdc = dc3.my.domain.com
   kdc = dc4.my.domain.com
   kdc = dc5.my.domain.com

  # Admin server is a list of AD server
  #admin_server = adsrv1 adsrv2 ... adsrvX
  ##ADMINSERVER##
   admin_server =  dc1.my.domain.com dc2.my.domain.com dc3.my.domain.com dc4.my.domain.com dc5.my.domain.com

 }

##MyRealms##

[domain_realm]
 .my.domain.com = MY.DOMAIN.COM
 my.domain.com = MY.DOMAIN.COM

##MyDomRealms##

smb.conf

[global]
server string = my server
workgroup = MY
security = ads
realm = my.domain.com
password server = *
domain logons = no
template homedir = /home/%D/%U
template shell = /bin/bash
winbind enum groups = no
winbind enum users = no
winbind use default domain = yes
domain master = no
local master = no
prefered master = no
os level = 0
idmap config *:backend = tdb
idmap config *:range = 11000-20000
idmap config MY:backend = rid
idmap config MY:range = 100000-200000