NTFS Partition WOnt Mount in Win 10 Until I Install HFS+ and ExtFS Drivers

Ok, something weird.

I had a Thinkpad P70 (UEFI) with Windows 10 (Creators) & an SSD as a second disk with an NTFS partition working fine. Then I had to repave the laptop with the OEM Recovery Windows 10 (1703). The reinstall went well but now the NTFS partition failed to mount, but otherwise showed as happy and the right size in Disk Manager, all the options from right clicking on the drive were greyed out except for Delete Volume. Diskpart didn't know what the filesystem was either but showed the correct sizes and partitions.

Took the drive out, hooked it up via USB to the Thinkpad, same result. Hooked it up to another PC and a MBP, same result. Put the drive back in the Thinkpad, installed HDM 15 Pro, showed the same thing, not showing as NTFS, correct sizes and positions of the other partitions.

Reinstalled Paragon HFS+ and ExtFS drivers, rebooted and BOOM, partition mounts, all the data is fine.

Any idea whats going on?