MRZ is the machine readable zone (i.e. the lines on the bottom of the data/photo page). This is scanned with the camera, and used as a decryption key to read the data over NFC.

This is why all biometric readers in airports require you to insert the passport with the photo page open, because it needs to grab that key before it can actually read the chip.

So either something's broken in the AC app, or it misread the MRZ. I'd try again, making sure the passport is unmoving on a flat surface, and your hand is steady with your phone (maybe prop it against something to keep it still).

On Android, you can use https://play.google.com/store/apps/details?id=app.iris to read your passport. If that doesn't work, then ... something might be broken in your passport.

From https://www.afar.com/magazine/the-de...-your-passport, "Thanks to a special piece of security tape buried in the cover of your passport, the data on the chip cannot be read when the passport book is closed."

I know for a fact that's not accurate (given I just used the app while my US passport was closed). But it might also be worth trying it with your passport open, holding your phone to the inside of the cover.

Actually, it also says "the only people who can read what’s on your passport book’s chip are border officials with the right cryptographic credentials", which is... obviously wrong.