There are several places in Magento where IPv6 addresses are not shown properly. The fix differs for each part of Magento that shows the wrong IPv6 address and so it can not be discussed here in detail. If you need help fixing the IPv6 problem for your Magento shop, please contact me. I know how to solve that problem.
Fixing the IPv6 problem
You want or need help implementing this solution? Maybe you did not find what you were looking for? Contact me and I will assist you with whatever Magento problem troubles you!