I’m also using v.2.2.15 (1194), and–like Billy–have no rocket.
Also starting today, I have no completion symbol (white circle outline that turns into a yellow checkmark circle)–only the completion chime, and the wrong day of the week. Shows Monday, today’s Friday. Means we’ve gone from being off by two days to being off by three.
The date and time are correct on my iPhone.
Needless to say, it’s ironic that the “Do you like Memrise?” graphic appeared on the same morning the app failed to show I’ve completed the day’s lesson. Had there been a third option for “wildly frustrated,” my finger would have slid that direction.