ipv6 connectivity issues after update to 20260707 userland

Hi!

After updating my NetBSD kernel + userland to 20260707, one of the new
problems I saw was that I had no IPv6 connectivity any longer.

Replacing the kernel with the previous one didn't change anything.

So now I also tried replacing the userland with the 20260626 one, and
my IPv6 connectivity is back (directly after a reboot, and previous
reboots with kernel changes didn't change anything).

I've compared 'ifconfig -a' between working and non-working, the only
difference is for tap0 and the order of the inet6 entries for my main
network interface changed.

'route show' shows two more hosts on the newer kernel+userland, and
the 'default' Gateway has a different address, the XXXX:XX bytes
differ in the "fe80::XXXX:XXff:fe".

I don't how to debug this. Does someone have an idea what could be the
problem here?

Is anyone else seeing this?
 Thomas