Can you clarify what you're referring to as the "Compiler Utility"? If you haven't done so already, please give PXToolkit a try. It's a free to download and use for your personal projects, works on Windows, and should make it straightforward to import your sample and create an instrument ready to load on your Prophet X.
Among other things, you've mentioned "all the A3s" which suggests that you have more than one sample per note. If you're using 8dio's official utility then you've run into its obvious limitation: it doesn't support samples at multiple velocities, nor does it support round-robin alternates. PXToolkit supports both of these features along with everything else the Prophet X is capable of understanding.
I'm not doing multiple velocities or multiple samples per note. I'm just trying to assign one sample per note. When I mention "All the A#s", I mean A#0, A#1, A#2, etc.
The Compiler Utility is the 8Dio one I downloaded a while back. I do have the PX toolkit & I will try that next.
The problem I ran into with the 8Dio app is that, even though I named each sample correctly to its designated key on the keyboard, and then dragged each correct sample to its single designated area in the app, when I imported this package all the As - A0, A1, A2, A3, A4, A5 - mapped to E0, F0, F#0, G0, G#0, A0. A#s did the same thing, as did the rest of the samples all the way up to the G#s.
Something must have happened in the app that read something else in each WAV file I imported. Maybe it read the date stamps or something else in the files & assigned them that way? That doesn't make sense in that I did save out each file going from the lowest to the highest, as I had originally sampled them. If there was some sort of metadata, like assigning the title of the file, that might make sense but I did try that & it didn't change anything.
Anyway, I'll try PX Toolkit & see what I get. Thanks for your input, I really do appreciate it!!