Sandisk SSD USB not detected by Android I have a Sandisk Extreme Portable SSD 500 GB. It works fine with Windows 10 but it cannot be detected by any of my Android devices. I tested with an Nokia 3.1, Sony Xperia Z3 Tablet Compact and a Sony Xperia 10 Plus, both with and without a Transcend OTG adapter. As well, I reformated it with exFAT and NTFS. What could be wrong?

The tablet runs Android 6 while the two phones run Android 9.

Other USB memory sticks work fine with the OTG adapter on all devices.
There are one major differences between an USB stick and an USB SSD: power consumption

As SSDs usually don't have the possibility to use a separate power supply you have to place a active USB hub (a hub with an own power supply) between the phone and the SSD.

The SSD is optimized for high performance and therefore requires much more power than a simple USB stick. 

The Sandisk Extreme Portable SSD 500 GB requires about 4 Watt.
Usually smartphone only support USB 2.0 and therefore the output is limited to 5V at 500 mA = 2.5 Watt. Only a very few smartphone support USB 3.0 or USB power delivery in OTG mode which would make it possible to use an SSD via OTG.

On a regular computer the SSD works because USB 3.0 allows 900 mA (5V at 900mA -> 4.5 Watt) and therefore it can power the SSD correctly.