TRIM not supported according to zfs, but supported according to hdparm

[TN22]

Running TN Scale; digging into why my weekly TRIM task fails for one volume, comprised of two 2TB Team CX2 SSDs -

root@nas[~]# zpool trim BACKUP
cannot trim: no devices in pool support trim operations

yet...

root@nas[~]# hdparm -I /dev/sde | grep -i trim
* Data Set Management TRIM supported (limit 8 blocks)
root@nas[~]# hdparm -I /dev/sdf | grep -i trim
* Data Set Management TRIM supported (limit 8 blocks)

What am I missing? These disks are connected to the same controller as my other pool (Samsung 860 SSDs) which does work fine.