OpenVZ 7 node IPv6 issue after update

I am wondering anyone here still using OpenVZ 7 sees the new IPv6 related issues after upgrading to version 3.10.0-1160.80.1.vz7.191.4

Initially when installing container IPv6 works fine, but randomly dies after a while on some of the containers.
From container -

Some containers have working IPv6 , some don't.

The host node is unaffected by this issue:

[root@dro2-nld ~]# ping6 google.com
PING google.com(ams15s41-in-x0e.1e100.net (2a00:1450:400e:802::200e)) 56 data bytes
64 bytes from ams16s21-in-x0e.1e100.net (2a00:1450:400e:802::200e): icmp_seq=1 ttl=120 time=4.74 ms
64 bytes from ams16s21-in-x0e.1e100.net (2a00:1450:400e:802::200e): icmp_seq=2 ttl=120 time=2.78 ms
64 bytes from ams16s21-in-x0e.1e100.net (2a00:1450:400e:802::200e): icmp_seq=3 ttl=120 time=3.04 ms
64 bytes from ams16s21-in-x0e.1e100.net (2a00:1450:400e:802::200e): icmp_seq=4 ttl=120 time=2.73 ms
64 bytes from ams16s21-in-x0e.1e100.net (2a00:1450:400e:802::200e): icmp_seq=5 ttl=120 time=2.82 ms
^C
--- google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4005ms
rtt min/avg/max/mdev = 2.734/3.225/4.742/0.767 ms

Checking it further ,

I made a test VM and assigned it IPv6 '2001:41d0:a:28b6:7cbb:0000:0000:0001'

Tried pinging the address and it was not reachable globally https://prnt.sc/vmRGmN2P0UDZ

I added that IPv6 address to the host node network interface
ip -6 addr add 2001:41d0:a:28b6:7cbb:0000:0000:0001/80 dev br0

It responds to pings now https://prnt.sc/CdgToWos2TFZ

I removed the IPv6 address from the host node network interface ip -6 addr del 2001:41d0:a:28b6:7cbb:0000:0000:0001/80 dev br0

It still responds to ping fine https://prnt.sc/3prDDpT7I_z7

The container has working IPv6 connectivity now

root@test:/# ping6 google.com
PING google.com(par21s20-in-x0e.1e100.net (2a00:1450:4007:818::200e)) 56 data bytes
64 bytes from par21s20-in-x0e.1e100.net (2a00:1450:4007:818::200e): icmp_seq=1 ttl=115 time=4.69 ms
64 bytes from par21s20-in-x0e.1e100.net (2a00:1450:4007:818::200e): icmp_seq=2 ttl=115 time=4.64 ms
64 bytes from par21s20-in-x0e.1e100.net (2a00:1450:4007:818::200e): icmp_seq=3 ttl=115 time=4.79 ms
^C
--- google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 5ms
rtt min/avg/max/mdev = 4.637/4.703/4.785/0.100 ms

This issue did not exist in previous openvz versions and appeared after the upgrade.

Any idea what is causing this ? I think using ndpresponder will resolve this issue, but I haven't figured how to configure it yet.