There was a bug in zfs 2.3.0 / 2.3.1. zfs was supposed to prevent incompatible kernels from installing, but instead only prevented the kernel-devel packages from incompatible kernels from installing (but still allowed kernel-core to install). This led to installing a kernel that could not build the zfs kmods since that kernel’s kernel-devel package was blocked. Which is not-so-great if you use zfs on root.
This bug has been fixed in zfs 2.3.2. Kernels that are incompatible with zfs now are automatically blocked by dnf until zfs gets updated to support the new kernel. dnf continues to work normally, and you dont need to manually exclude updating the kernel from dnf update…itll update the kernel after it updates zfs. Basically, dnf update now “just works”.