Encrypted disk is "corrupt" but unencrypted is fine

I have a USB hard drive that I want to use as my Time Machine backup disk. I want it to be encrypted.

If I partition it as an encrypted disk, it finishes fine; but then if I run First Aid, it says it’s corrupt. If I partition it UNencrypted, First Aid says it’s fine. I’ve repeated it multiple times. Encrypted = corrupt. Unencrypted = okay.

Why would the disk only read as corrupt when encrypted?

Running OS 10.15 on a 2014 MacBook

This is the First Aid log when I get the error. If it’s unencrypted, it’s short and sweet — all "okay".

Running First Aid on “WD easystore 25FA Media” (disk2)

Checking prerequisites
Checking the partition list
Checking the partition map size
Checking for an EFI system partition
Checking the EFI system partition’s size
Checking the EFI system partition’s file system
Checking the EFI system partition’s folder content
Checking all HFS data partition loader spaces
Checking booter partitions
Checking booter partition disk2s3
Verifying file system.
Volume is already unmounted.
Performing fsck_hfs -fn -x /dev/rdisk2s3
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Checking extended attributes file.
Checking volume bitmap.
Checking volume information.
The volume Boot OS X appears to be OK.
File system check exit code is 0.
Restoring the original state found as unmounted.
Checking Core Storage Physical Volume partitions
Verifying storage system
Performing fsck_cs -n -x --lv --uuid 0AD74A3C-D0D6-42F5-B0D4-9FB8486ABC99
Checking volume
disk2s2: Scan for Volume Headers
disk2s2: Scan for Disk Labels
Logical Volume Group 0AD74A3C-D0D6-42F5-B0D4-9FB8486ABC99 on 1 device
disk2s2: Scan for Metadata Volume
Logical Volume Group has a 24 MB Metadata Volume with double redundancy
Start scanning metadata for a valid checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Load and verify Transaction Segment
Incorporate 1 newer non-checkpoint transaction
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Load and verify Metadata Superblock
Load and verify Logical Volumes B-Trees
Logical Volume Group contains 1 Logical Volume
Load and verify 2C6C36E4-9E7A-433B-847C-BEE4D39BFBF2
Load and verify B8B932A7-B825-48D5-A577-5485DDD0DE76
Load and verify Freespace Summary
Load and verify Block Accounting
Blocks on device 26EC24D8-82B4-4CA5-B361-FB2194641A72 are not accounted for by CoreStorage
Unable to bootstrap transaction group 6: inconsistent crosscheck
Continue scanning metadata for an older checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Incorporate 0 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Load and verify Metadata Superblock
Load and verify Logical Volumes B-Trees
Logical Volume Group contains 0 Logical Volumes
Load and verify Freespace Summary
Load and verify Block Accounting
Blocks on device 26EC24D8-82B4-4CA5-B361-FB2194641A72 are not accounted for by CoreStorage
Unable to bootstrap transaction group 5: inconsistent crosscheck
Continue scanning metadata for an older checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Incorporate 0 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Load and verify Metadata Superblock
Load and verify Logical Volumes B-Trees
Logical Volume Group contains 0 Logical Volumes
Load and verify Freespace Summary
Load and verify Block Accounting
Blocks on device 26EC24D8-82B4-4CA5-B361-FB2194641A72 are not accounted for by CoreStorage
Unable to bootstrap transaction group 4: inconsistent crosscheck
Continue scanning metadata for an older checkpoint
Load and verify Segment Headers
Load and verify Checkpoint Payload
Load and verify Transaction Segment
Incorporate 0 newer non-checkpoint transactions
Load and verify Virtual Address Table
Load and verify Segment Usage Table
Load and verify Metadata Superblock
Load and verify Logical Volumes B-Trees
Logical Volume Group contains 0 Logical Volumes
Load and verify Freespace Summary
Load and verify Block Accounting
Blocks on device 26EC24D8-82B4-4CA5-B361-FB2194641A72 are not accounted for by CoreStorage
Unable to bootstrap transaction group 3: inconsistent crosscheck
No valid commit checkpoint found
The volume 0AD74A3C-D0D6-42F5-B0D4-9FB8486ABC99 was found corrupt and needs to be repaired
Storage system check exit code is 1.
Problems were found with the partition map which might prevent booting
Storage system verify or repair failed. : (-69716)

Operation successful.