"No L2ARC Here" but cache disks are present in ZFS

I replaced the cache disks on my ZFS server and everything seems fine to me:

$ zpool status  pool: storage  state: ONLINE   scan: scrub repaired 0B in 1 days 09:44:40 with 0 errors on Tue Jan 21 17:50:23 2025  config:    NAME                                                  STATE     READ WRITE CKSUM    storage                                               ONLINE       0     0     0      .      .      .    cache      sdu                                                 ONLINE       0     0     0      sdw                                                 ONLINE       0     0     0

However when I try to query the l2arc with arcstat I get this error message:

$ arcstat -f l2hitsNo L2ARC Herel2hitsIncompatible field specified! -- ['l2hits']Usage: arcstat [-havxp] [-f fields] [-o file] [-s string] [interval [count]]  .  .  .

I might be missing something trivial but I cannot figure out what, and the web is not very helpful in this regard.

I'm using zfs-2.1.16-1 on Rocky Linux 9.5.