While reviewing transactions today on my iPhone (by pressing the blue arrow button in a budget category), I noticed that the dates were wrong. They say all kinds of odd things - my mortgage paid on 6/2 and 5/1 shows as paid on May 19 and April 19. I checked a number of different budget categories and their transactions and it seems like many have this same issue.
If I actually select each transaction from that transaction list screen and go to the more detailed screen about it, it shows the correct dates.
YNAB on the desktop is totally fine. I can't believe I would be the only one who experienced this, but I don't see any other bug posts here on it.