Why ntpstat command isn't working well with ipv6 ntp implementation?

Issue

• Ntp client server is on ipv6 stack. Everything works fine except ntpstat command. It generate unexpected result?

[root@example.com ~]# cat /etc/ntp.conf
disable monitor
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
server -6 2a00:5aXX:XXXX::cc8:XXXX 
driftfile /var/lib/ntp/drift

[root@example.com ~]# service ntpd restart
Shutting down ntpd:                                        [  OK  ]
Starting ntpd:                                                   [  OK  ]
[root@example.com ~]#

[root@example.com ~]# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*2a00:5aXX:XXXX::cc8 192.168.1.2      2 u   44   64    1   49.808   -0.291   0.000

• Output of ntpstat command showing ipv4 address. Synchronised to NTP server (239.221.166.176).

[root@example.com ~]# ntpstat
synchronised to NTP server (239.221.166.176) at stratum 3  
   time correct to within 7982 ms
   polling server every 64 s