I stumbled in this same bug because I used the latest xanmod kernels.
This was already fixed sometime ago in the openzfs repo: https://github.com/openzfs/zfs/commit/3c8665cb5d62c42d6ef74e269f146ae17c440229
I tried a manual patch but dkms still fail to build.Easy fix was to use lts version of xanmod instead of main/edge, since still in 6.18.
