I updated to the iOS 3.1.9 version and it has broken streaks. My streak yesterday in the Hebrew course I’ve been working on was 983. Today it showed 984 and already completed. After the first review it jumped to 982 and showed partially completed. After the second review it jumped to 983 and showed completed. My German 7 streak is one day behind as well.
edited to fix version: it was 3.1.9 (not 3.1.8) that did this