@ND3JR Raspberry Pi (when used without UEFI) needs a kernel in a custom format for its special firmware, this kernel is stored as /boot/netbsd.img from what I remember. Since it's in a different location from usual, it's possible it didn't get updated. You can pull the SD card out and update it by hand.

http://cdn.netbsd.org/pub/NetBSD/NetBSD-11.0/evbarm-aarch64/binary/kernel/netbsd-GENERIC64.img.gz