iXpand 256 GB not working with iphone 7 plus

I just bought an iXpand 256 GB and my iphone 7 plus does not recognize it at all.  My Windows 10 PC does recognize it.  I have updated the firmware of it and it says it has the most recent version.  I have the newest versions of the ixpand apps.  The iphone is running IOS 12.1.1.  I have performed all the steps found here:


So I have forced closed all apps on the phone and restarted the iphone and done every step I can find.  The phone and apps just completely ignore it when I plug it into the phone…  but the PC sees it right away - what else can I do?


I don’t think that you can expand the data storage on Apple products. 

I found the solution - there are 3 programs in the Apple App Store with almost identical names and look/feel - the two I had downloaded that came up first in the search when I plugged in the 256 GB Sandisk iXpand were not the right programs even though they looked like the pictures on line…  I later plugged it into my ipad and when it took me to the app store, the correct (and different program) appeared in the search results.  Once I download it, it all worked - that probably explains why so many people have this issue - there are several programs with similar names!