External SSD shows in system information, but nowhere else on my MacBook Pro

Disk Utility is the Grand arbiter between Physical Volumes and mountable Volumes.

launch Disk Utility and look for the Physical device. in cases like this, the Disk Utility View default of "show only Volumes" get is the way of understanding. Use the tiny 'View' Icon to change to "show all devices".

Select the Physical device in question.

If it has no additional Items below it, post a screenshot or choose GetInfo off Disk Utility's File Menu and post that.

if it has what appear to be sensible items intended under the Physical Volume, Use the RepairDisk/FirstAid Icon to select and repair in order, the Physical Device, the Container-Disk (if any), and the Mountable Volume(s) (if any). if it gets stuck without repairing completely, try at least once more.

There is a very simple-to-use Mount button here as well.

let is know how you make out.

Check whether OWC has updated firmware for whichever SSD is involved here, too.