macOS 14.4 Seems to Break stable IPv6 'autoconf secured' address

Recently there is instability in macOS reliably generating stable 'autoconf secured' IPv6 address upon reboot. Mine is a stateless IPv6 environment. This seems to be correlated with update to 14.4 (23E214). However, I've insufficient logging and timing to really place the blame on the update. Perhaps it's slightly older. Is this a bug in the OS? …a new feature? Has anyone else noticed such behavior; their network interfaces assigning/generating these random addresses? These should be quite stable provided that the local VLAN and network prefix is also stable. I'm not interested in disabling macOS's default use of autoconf temporary addresses in order to land on a static address. I'm not interested in reconfiguring the LAN to a stateful implementation. Here are some relevant kernel settings: user@host:~ $ sysctl -a | grep tempaddr net.inet6.ip6.use_tempaddr: 1 net.inet6.ip6.prefer_tempaddr: 1 net.inet6.ip6.ula_use_tempaddr: 0 …hope someone out there has some thoughts.