The IPs hosted on an interface that is not the current IPv6 default gateway interface are not reachable outside the current IPv6 subnet

IPv6 addresses configured on a non-default gateway interface are not reachable from outside the current subnet and are unable to use the current default gateway. Only IPv6 addresses that are hosted on the current default IPv6 gateway interface are reachable using the gateway.

(3596284)

Workaround:

Do not use IPs that are currently not online on the default gateway interface for cluster communication outside the current subnet.