freebsd-update - just partly

Hi,

I just updated 3 of my 15.0-RELEASE systems. However, two of my 
production systems which are NOT running with pkgbase after a reboot 
still report the kernel to be 15.0-RELEASE (and since there is a zfs 
errata with a fix this seems odd). A test VM running pkgbase after a 
reboot reports 15.0-RELEASE-p1 kernel. Userland is 15.0-RELEASE-p1 on 
all systems. How can I fix this?

Regards,

Robert