Write to a person. It is a small operation.
wuyuxai@gmail.com — usually answered within a day or two.
Send the photo if you can. Head-on, filling the frame, and even light help most; a figure at an angle in shadow is the hardest case. If it offered two and you had to choose, that is the app working as intended — the difference between some variants is one printed detail.
This version identifies one at a time. Crop to a single figure and try again.
Settings → Restore purchases, with the same Apple Account you bought it on.
Both devices need iCloud switched on and the same Apple Account. If you would rather not use iCloud, export a file from one and import it on the other.
The catalogue comes from Rebrickable and updates monthly. If something is missing there, it is missing here — telling them fixes it for everyone.