Hybrid apps: the native code and the embedded WKWebView each track their own analytics session, so one user doing one thing shows up as two unrelated sessions. The fix is architectural, not clever, pick one side to own the session and stitch them tougher by sending events with the ids. After that it’s just bookkeeping: keeping the two in sync across session rotations, cold starts, and one side restarting while the other is still alive.