Please allow some time for the configuration.

And also please note For Ubuntu & Debian instance needs to enable IPV6 manually after configuring. Kindly follow the below-mentioned steps to enable the IPv6 address for your server.

Login to your server via ssh connection and adding the the below entries in sysctl.conf file:

nano /etc/sysctl.conf

Scroll all the way down, and add the following lines at the end:

net.ipv6.conf.all.autoconf = 0
net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.eth0.autoconf = 0
net.ipv6.conf.eth0.accept_ra = 0

To check run:

sysctl -p 

Then try to restart network

systemctl restart networking

Then check with

ping6 google.com

If its still not working try to reboot your VPS once.

Note: Lastly, also ensure that your /etc/sysctl.conf file does not have any values in place that might be disabling IPv6 connectivity. If it does, be sure to comment those out and refresh your settings afterwards by using "sysctl -p" or by rebooting your VPS.