(Android): Where did my files go? And how did I get them back?

[StephenG1CMZ]

I recently noticed that everything disappeared - Programs and Notes definitely, I can't be sure about Lists as the first page of my lists were empty anyway.
The Android Pro App had updated from 13333 to 13443.
But I had thought that was a coincidence, as a couple of days ago I remember seeing a "Are you sure you want to delete" message as I was putting the phone away - perhaps I clicked the wrong button?

Today, I cleared the Android Apps' cache for all apps, increasing the available space from about 440 MB to about 770 MB. Then updated some other Apps (not the Prime), reducing space to about 660 MB.

I just opened the HP Prime Pro app and was surprised to see my programs are back from wherever they had gone to!

I definitely didn't try any sort of "restore" within the Prime app.

I am curious as to where my programs might have gone and what exactly caused them to reappear???

One hypothesis is that the update from 13333 to 13443 ran out of space and when I cleared some space on the Android it was able to complete copying the files from 13333 to 13443.

Any other explanations?