SanDisk external SSD does not show up on desktop

Update: before calling Apple Support I looked once again at the settings of "Cd's, dvd's and iPods" and "External drives". These settings can be found in two sub-menu's,

1. Finder menu > Preferences > General > Show these items on the Desktop, and

2. Finder menu > Preferences > Navigation column > Devices

The supplier's helpdesk has adviced me to unmark "Cd's, dvd's and iPods" (to remove the "non-local drive") and to mark "External drives" and I followed orders in the first sub-menu.

Looking at the second one, I changed "Cd's, dvd's and iPods" from unmarked to marked.

Believe it or not, the icon of the SanDisk SSD appeared, accessible like the Samsung.

Even stranger, from now on the functionality of the SanDisk SSD is not affected by marking or unmarking "Cd's, dvd's and iPods" in the second sub-menu. It remains accessible.

This solved my problem although I do not know how. Anyway, I would like to thank all those who have spend some of their valuable time trying to help me out.

The help desk of the supplier of the SSD told me that External Disks should be marked, so I took care of that.

For your information: for regular back ups with Time Machine I use a Samsung portable SSD also connected thru a usb-c, this works fine.

Thank you anyway.

The 1st linked article started with how to use the "diskutil list " command in Terminal.

Using this command shows the before mentioned Samsung external SSD (which works niceley).

No mentioning of a SanDisk external SSD, however.

This is consistent with the output in the navigation bar of the DiskUtility app.

It should be noted that the "non-local drive"problem is not a general problem with all kind of Macs: the SanDisk SSD is accessible on Macs with a usb-A connection. The website of SanDisk assures that all Macs with MacOS 10.9+ are compatible. Imho that means usb-A as well as usb-c.

The SanDisc SSD is supplied with a usb-c cable and an additional extension for use with usb-A devices