Is Game Review Broken?

Hi,

I played a game against a chess app on my phone as I was walking home from a quiz night.  This is only level 5 of the app, and it's not very good (as you will see), but it's not the game so much as the output of the game review that looks odd.  For example, at the end of the review it will give an overall "accuracy" score for both players, and you get a break down of accuracy for the opening, middle game, and end game phase of the game.  And of course there's the "estimated Elo".

For this game, the review gave me (black) just over 90% accuracy, and gave the app around 83%.  However, while it produced an "opening" accuracy score, for both the middle game and end game it gave nothing other than to say "this phase of the game could not be graded due to lack of relevant moves", which of course is rubbish.

I know that the estimated Elo factors in the rating of the players.  As the app  doesn't have a rating, I left that out and just entered my own (857).  While I don't really trust the values it gives at the best of times, for this game it listed me as 2150 and the app as 1050!  Clearly, neither of those is reasonable.

Anyway, I'm just wondering if anyone else is having similarly weird outputs?  Maybe it's limited to uploaded games (into my collections area)?  Or maybe it has to do with not entering some sort of Elo for White?

Any thoughts?