Cryptfs : Unexpected value for crypto key location Phone: Samsung S9 Plus, 256Gb
OS: Lineage OS 17.1 (Android 10)
ROOT: TWRP 3.5

I installed Lineage OS 17.1 on a Samsung S9+. It's been working fine so far. However, when I encrypt the OS from the security menu, right after the screen goes black with the green android-like logo, the phone quickly reboots back to the non encrypted OS. Going again through the process does not help.
logcat shows:
--------- beginning of main
01-20 19:17:52.959 4019 4129 D vold : fdeEnable(3, *, 0)
01-20 19:17:52.960 4019 4129 D vold : !fscrypt_is_native, spawning fdeEnableInternal
01-20 19:17:52.960 4019 403 E Cryptfs : Unexpected value for crypto key location
01-20 19:17:52.961 4019 403 E Cryptfs : Cannot get size of block device
01-20 19:17:53.067 4019 403 W vold : Found symlink /proc/29802/cwd referencing /data/misc/keystore
01-20 19:17:53.067 4019 403 W vold : Found symlink /proc/29803/fd/7 referencing /data/vendor/gps/.lhd.lock
01-20 19:17:53.068 4019 403 W vold : Found symlink /proc/29803/fd/12 referencing /data/vendor/gps/.pipe.gpsd_to_lhd.to_server
01-20 19:17:53.068 4019 403 W vold : Found symlink /proc/29803/fd/14 referencing /data/vendor/gps/.pipe.gpsd_to_lhd.to_client
01-20 19:17:53.069 4019 403 W vold : Found symlink /proc/29804/fd/7 referencing /data/vendor/gps/.gpsd.lock
...
...
01-20 19:17:53.217 4019 403 W vold : Sending Killed to 32740
01-20 19:17:53.218 4019 403 W vold : Sending Killed to 32509
01-20 19:17:53.218 4019 403 W vold : Sending Killed to 32383
...
...
01-20 19:17:53.221 4019 403 E Cryptfs : Unexpected value for crypto key location
01-20 19:17:53.221 4019 403 E Cryptfs : Cannot get size of block device
--------- beginning of crash

I tried the steps given here on /data (/dev/block/sda25), but it did not do it for me either.

Any idea on how I can debug further Cryptfs : Unexpected value for crypto key location?
Is there a way to encrypt /data via the command line if this keeps failing?
this device is encrypted with FDE full-disk-encryption. depending on how you installed Magisk the forceencrypt= flag is gone. that's what the &quot;crypto key location&quot; refer. edit your fstab and restore encryptable= flag that might help to use Samsung encryption in boot mode. but TWRP is most likely not able to decrypt anyway, so there is no benefit of having TWRP
btw this is a well known Magisk Bug and topjohnwu decided to ignore my fix