Question about Transcend JetDrive 850

I have a "MacBook Pro (Retina, 13", end of 2013)" and immediately after delivery I installed the ssd "960 GB
Solid-State PCI Express Hard Drive" immediately after delivery. Unfortunately, I was unable to find a suitable usb enclosure for the older, slower and much smaller original ssd at a reasonable price.

Don't they still have the 2.5" sdd? I installed it in my MacBook Pro early 2015. But still had to have it set up.
Now with the last macOS update there were problems again. It didn't work, although apple said it should work. I'm not sure if it's because of this sdd.