That’s similar to what mine does. I have blocks of terms that pass without repetition, then at the end of it, 1-3 terms repeat, and then the app pauses and spins. The variable is the size of the block: I haven’t counted out the range, but offhand I’d guess it goes from 3-10 terms. Sometimes the app checks in (spins) every other term, sometimes it takes a while longer, but it never goes above about 10 before I see repetition.
And my queue is up around 5500 now, and for the last 24-36 hours the app has been stuck in another “fetching next” loop, so it’s completely unusable. I have serious doubts that I’ll ever get it cleared now.