GPT NTFS Volume Not Being Identified As Such. Bad Disk or Bug?

[jwshields]

Hello!
I'm running into a weird problem with this tool. I'm not sure if it's because of the tool or because of how I've tried [re]formatting my disks, but I wanted to make a report here and see if something was up, or if I just really broke my filesystems (or my disks...)
I am leaning toward the idea that my disks may be borked, but I'm stumped as to why all my testing and reports are so inconsistent.

Anyway -
I have a decent number of disks on my local machine, just added three new ones, all formatted as GPT and using NTFS, two of the disks are 18T raw, the third is 20T raw. I seem to only be having this issue with the 18T disks (Model ST18000NM003J-2TV102)

I've tried formatting the disks multiple ways.

1. Initializing the disk through Windows 10, creating a simple NTFS partition, quick format
2. After that, I wiped the disk using pv < /dev/zero > /dev/sdb for about 64GiB, used fdisk to create a new GPT partitioning scheme, used mkfs.ntfs will a full zero format to create a new NTFS partition
3. After that, I wiped the disk again, only by deleting the partitions in gparted, and recreated an NTFS partition using gparted and a quick format
4. Used pv to zero the first few tens of GB of the disk, used Windows to reinitialize the disk and perform a quick format
5. Used Windows to convert the partition from NTFS to REFS and back, and performed a quick format.

Between each format or wipe & recreation, I ran through a series of tests, trying to view the MFT, volume info, partition info, defragging, and a few other "misc" non-scientific tests to validate the new partition was functional - and throughout those "tests" is where I found the inconsistencies with ntfstool.

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My findings:

1. chkdsk reports all three disks as healthy/no bad sectors/no bad MFT/etc
2. analyzing/defragmenting using Ultimate Defrag by Distrix fails on the 18T disks
3. Sysinternals NTFSInfo reports are nearly identical for all three disks (mainly, I mean, no errors)
4. fsutil.exe reports for all three disks are nearly identical and no errors are reported.
5. Active@ Disk Editor reports all three disks are healthy ("Volume Integrity Info" is all ✅ about Primary & Mirror entries for MFT, MFTMrr, LogFile, Volume, Root, BitMap, Boot, etc) --- BUT --- Active@ DE allows editing the boot sectors. For the 20T disk, it reports all is well with the PBS & CBS; for the 18T disks, it reports that both the PBS and CBS have invalid values in hex key 40, "Clusters per MFT record" - with a hex value of F6 - it suggests it should be F4 - cross checking some of my other disks (20T and a few SSDs and some 8T HDDs) - they all have F4 for that key.
6. ntfstool has some weird reports for the two 18T disks when I query them using ntfstool gpt, but things appear to be "weird" when running it with the info param. Other commands like mft.*, reparse, shell, shadow - also do not work on the 18T disks

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I've created a gist where I've dumped a bunch of output from ntfsinfo.
Output of ntfstool info: https://gist.github.com/jwshields/403d5b01e430108bd289bf8947325c89#file-ntfstool-info
Output of ntfstool gpt: https://gist.github.com/jwshields/403d5b01e430108bd289bf8947325c89#file-ntfstool-gpt
I've also created a screenshot of the disk management menu in windows, showing most of my disks; I've highlighted the three I'm focusing though.

Plainly, I just don't understand.
Is this a bug in ntfstool, somehow? or is there a problem with my disks?
Above, I listed a bunch of ways I attempted to format the disks, each iteration seemed to give me the same results (ie, "Invalid or non-GPT partition table" - as well as Distrix UD failures when attempting to defrag), no matter how I wiped nor created the partions.
Willing to provide any further information if needed, I'm also not attempting to look for spoonfeeding help here. If this is some weird bug, I'm more than happy to help out and give info, but if this is because my disks are bad, or my own stupidity, I'll concede without issue.

Thank you in advance, and thanks for such an awesome tool!