Static IPv6 assignment issue

Hi,

Multiple IPv6 Global IP’s are being assigned to my container, loosing connectivity.

In my current set up I have my custom docker network bridge (br0)

docker network create --ipv6 --driver=‘bridge’ --subnet=xxx.xxx.147.140/24 --subnet=xxxx:xxxx:0:2::8d/64 --gateway=xxx.xxx.147.140 --gateway=xxxx:c680:0:2::8d --aux-address=DefaultGatewayIPv4=xxx.xxx.147.1 --aux-address=DefaultGatewayIPv6=xxxx:xxxx:0:2::1 --opt=com.docker.network.bridge.name=br0 br0

Then I run the container specifying that network and a static IPv4 and IPv6 address which are correctly assigned to the container.
But an extra Global IPv6 comes from nowhere, gets assigned to eth0 inside the container and I loose connectivity.

ifconfig:
eth0 Link encap:Ethernet HWaddr 02:42:67:d6:93:8d
inet addr:xxx.xxx.147.141 Bcast:0.0.0.0 Mask:255.255.255.0
inet6 addr: xxxx:xxxx:0:2::8e/64 Scope:Global (The one I assigned)
inet6 addr: fe80::42:67ff:fed6:938d/64 Scope:Link
inet6 addr: xxxx:xxxx:0:2:42:67ff:fed6:938d/64 Scope:Global ( ???)

This second Global IPv6 makes me loose connectivity in the container and I can’t find a possible way to find where is it coming from.
(Manually deleting the IP works, but it’s a workaround - I need a solution)