Yes, it's the lottery of the Hilton App in my experience, made more complicated in the last year or so by the appearance of paid upgrade options when selecting a room.

More than a few times I have been presented with fewer than 5 (generally average) rooms of the type I have booked but a plethora of rooms that I could confirm if I just paid the extra money. And then my mind cycles through the "but as a Diamond I should be getting a better room for free" - and then I wonder whether, if I select a room, I won't then get upgraded even if a better room is available (some hotels choose to assume you want the one you've selected, some will still upgrade).

So I leave it and then I check back to see if better room choices become available - which they often do, but I still fret about the lowest floor only being available when I arrive at the desk, but I also know that if I select a room that's just OK, I won't be able to change it afterwards in the app.

I have decided I would be very happy indeed to be a customer persona for Hilton IT department when they next look at amending their app...