Not Mikrotik issue, but I hope the community can help.
ISP IPv6 prefix(/64) delegation on my router, this I distributing for clients(Ubuntu 18.04, 20.04 LTS - default network configurations) with SLAAC.
In the first step, I catch 3 IPv6 addresses(Global Unicast IPv6 Address, Temporary and Link Local) on clients.
If the prefix changed, each client gets two new addresses(global, temporary), but the old ones remain and so it’s continues.
How can this be repaired?