Elements 3tb not showing up in any media players only on PC

I have a elements 4tb I have reformatted changed to gtp I’ve tried all three different setups nothin* , ntfs assigned drive letter. this works fine in PC but when I plug into seagate freeagent android box or Himedia Q10 pro media box or Himedia HD900B or HD 910A it will not show up at all… I have a 3tb my book that works fine and shows up on all media players…I can’t figure this out…any ideas ? thx I’ve used many different brand hard drives to store movies never ran into this before only WD of course.
the manufactures do not list what HDrives are compatible or not since like 99% are…and I can’t return this drive either I’m stuck with it…

Most older media players (and Smart Tv’s) don’t support GPT (GUID Partition Table) partitioned hard drives.

They only support MBR (Master Boot Record) partitioned hard drives. (2TB Max)

Check all your drives … and you’ll most likely find your 3TB My Book is MBR (with 512 Byte Emulation) and your Elements 4TB (3TB?) is GPT Partition Table.

All new Hard drives now (from every manufacturer) are GPT Partitioned … MBR is Obsolete.

Hi, thx for your input. so I checked my c drive and other externals…
C drive is MBR
my passport 3tb is GPT is seen by both tv and media players as are the following drives
seagate 1tb MBR
touro 3tb GPT
the My Book 4tb is GPT but unlike the Elements thats giving me the issue, in Disc management the elements shows the entire space available but the My Book 4tb for mac reformmated to NTFS has 200mb healthy (EFI system partition)
and 129mb of unallocated space in between those is the healthy 3725.99 available space, this drive shows up in any device, tv included…
all the drives I use are NTFS…
so my Smart 3d 4k samsung tv and all three media players including the latest Himedia Q10 pro with the latest firmware can support both MBR & GPT…I store concerts and movies on all these drives and never ran into a problem until now with this Elements 3tb drive…I use various brand drives, toshiba , Touro, WD, Seagate etc…