My Xbox One X does not recognize my External NVME SSD on startup.

You can or should be able to use it for the Series X but i don't recommend running your games from it,

as you wont get the fast loading or fast travel time of what the Series X custom NVMe SSD is capable of,

It's best to use any external HDD or SSD for just game storage and transfer you most played games onto the Series X NVMe SSD.

Well you csn technically store games on other nvme or ssd drives externally but they gotta be moved bacj to expansion offical seagate drive or intternal since the x series games relies on the super fast nvme

But only bc titles from one and older can run from external

Bear in mind, even faster SSD external storage only works for Xbox One and Xbox One X enhanced games. They won't work with Series X|S games. You can store these games on these drives, but you can't play them.

NVME is a waste of money as the USB 3.1 ports maximum bandwidth is 5Gb/s (or 500MB/s).

If you want an SSD for your Xbox One or Xbox One X enhanced games, then your best choice is a SATA SSD connected either via a SATA to USB 3.1 adaptor or an USB 3.1 external drive enclosure.

Ok what are you storing them on

If non nvme like ssd or mechanical drive rhen no it can't be installed on it

Either the xbox series x storage cards or internal nvme only

Patched or upgraded games must be stored on internal or storage card

Ir can be stored on external drives but can't run or upgrade from external

Must be moved internallu

You can still use external HDD for your Xbox/Xbox 360/Xbox One games but you can't play Series X/S games from them,

Series X/S games can only be played from the internal or external storage card,

with game file size's getting bigger, that 1Tb internal NVMe SSD is going fill up quick.