External EXFAT not mounting

Hello all,

I have a WD Elements 5TB External hard drive that is not mounting. I tried First Aid in Disk Utility and there was no issue found but it still isn't mounting.

Here's my iMac details:

macOS Catalina

iMac (Retina 5K, 27-inch, 2017)

Processor: 3.8GHz Quad-Core Intel Core i5

Memory 40GB 2400 MHz DDR4

Startup Disk Macintosh HD

Graphics Radeon Pro 580 8 GB

I turned to Terminal after reading some forums and here's what I did:

diskutil list

/dev/disk8 (external, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *5.0 TB   disk8

  1:    Microsoft Basic Data Elements        5.0 TB   disk8s1

Then I tried:

diskutil mount /dev/disk8

Volume on disk8 failed to mount

Perhaps the operation is not supported (kDAReturnUnsupported)

If it has a partitioning scheme, use "diskutil mountDisk"

If you think the volume is supported but damaged, try the "readOnly" option

Then I tried:

sudo fsck_exfat /dev/disk8s1

Password:

** Checking volume.

** Checking main boot region.

** Checking system files.

** Volume name is Elements.

** Checking upper case translation table.

** Checking file system hierarchy.

** Checking active bitmap.

** Rechecking main boot region.

** Rechecking alternate boot region.

** The volume Elements appears to be OK.

iMac03-Lidya:~ freestateproductions$ diskutil verifydisk disk8

Started partition map verification on disk8

Checking prerequisites

Checking the partition list

Problems were found with the partition map which might prevent booting

Error: -69770: Partition map check failed because no slices were found

How should I go about this without formatting the hard disk as it contains important overseas footage? Should I try mounting it on a PC?

Thank you in advance!