ashift = 0, can't run zdb on 13-current

[Matt Churchyard]

Hello,

I'm currently testing out encryption (using a recent snapshot of 13-CURRENT) on a backup system that will eventually go offsite once 13 is released.
I have created a pool just using default options but zpool output lists the ashift as 0:

root@:/etc/ssh # uname -a
FreeBSD  13.0-CURRENT FreeBSD 13.0-CURRENT #0 main-c255641-gf2b794e1e90: Thu Jan  7 06:25:26 UTC 2021     root at releng1.nyi.freebsd.org:/usr/obj/usr/src/amd64.amd64/sys/GENERIC  amd64
root@:/etc/ssh # zpool get ashift offsite
NAME     PROPERTY  VALUE   SOURCE
offsite  ashift    0       default

I'm sure it can't actually be 0. I've seen mentions online that this is a problem, but also that it just means "auto" ashift. Either way it's unnerving. I wanted to check with zdb, but this doesn't seem to run at all as I can find no cache file on the system and passing a pool name just gives "No such file or directory"

Is there any way I can run zdb on this system?

Regards,
Matt